I edited your stylesheet.css... It is now using a column width of 150px that you have set in your admin... You may want to increase that...

This should display the same in firefox and IE7 (but not tested thoroughly)

To fix it, I have changed several statements - mainly margin/padding/width values...




Code:
/* * Main CSS Stylesheet
 *
 * @package templateSystem
 * @copyright Copyright 2003-2006 Zen Cart Development Team
 * @copyright Portions Copyright 2003 osCommerce
 * @license http://www.zen-cart.com/license/2_0.txt GNU Public License V2.0
 * @version $Id: stylesheet.css 5349 2006-12-22 20:34:40Z birdbrain $
 */

body {
	margin: 24px 0 24px 0;
	font-family: verdana, arial, helvetica, sans-serif;
	font-size: 62.5%;
	color: #000000;
	background-image: url(../images/back.gif);
	background-repeat: repeat;
	}

a img {border: none; }

a:link, #navEZPagesTOC ul li a {
	color: #000000;
	text-decoration: none;
	}

a:visited {
	color: #333333;
	text-decoration: none;
	}

a:hover, #navEZPagesTOC ul li a:hover, #navMain ul li a:hover, #navSupp ul li a:hover, #navCatTabs ul li a:hover {
	color: #ff00ff;
	}

a:active {
	color: #333333;
	}

h1 {
	font-size: 1.5em;
	color: #9a9a9a;
	}

h2 {
	font-size: 1.4em;
	}

h3 {
	font-size: 1.3em;
	}

h4, h5, h6, LABEL, h4.optionName, LEGEND, ADDRESS, .sideBoxContent, .larger{
	font-size: 1.1em;
	}

.biggerText {
	font-size: 1.2em;
	}

h1, h2, h3, h4, h5, h6 {
	margin: 0.3em 0;
	}

/*  Might uncomment either or both of these if having problems with IE peekaboo bug:
h1, h2, h3, h4, h5, h6, p {
	position: relative;
	}
*html .centerColumn {
	height: 1%;
	}
*/

CODE {
	font-family: arial, verdana, helvetica, sans-serif;
	font-size: 1em;
	}

FORM, SELECT, INPUT {
	display: inline;
	font-size: 1em;
	margin: 0.1em;
	}

TEXTAREA {
	float: left;
	margin: auto;
	display: block;
	width: 95%;
	}

input:focus, select:focus, textarea:focus {
	background: #E4FEF5;
	}

FIELDSET {
	padding: 0.5em;
	margin: 0.5em 0em;
	border: 1px solid #cccccc;
	}

LEGEND {
	font-weight: bold;
	padding: 0.3em;
	}

LABEL, h4.optionName {
	line-height: 1.5em;
	padding: 0.2em;
	}

LABEL.checkboxLabel, LABEL.radioButtonLabel {
	margin: 0.5em 0.3em;
	}

#logo, .centerBoxContents, .specialsListBoxContents, .categoryListBoxContents, .centerBoxContentsAlsoPurch, .attribImg {
	float: left;
	}

LABEL.inputLabel {
	width: 9em;
	float: left;
	}

LABEL.inputLabelPayment {
	width: 14em;
	float: left;
	padding-left: 2.5em;
	}

LABEL.selectLabel, LABEL.switchedLabel, LABEL.uploadsLabel {
	width: 11em;
	float: left;
	}

#checkoutPayment LABEL.radioButtonLabel {
	font-weight: bold;
	}

P, ADDRESS {
	padding: 0.5em;
	}

ADDRESS {
	font-style: normal;
	}

.clearBoth {
	clear: both;
	}

HR {
	height: 1px;
	margin-top: 0.5em;
	border: none;
	border-bottom: 1px solid #9a9a9a;
	}

/*warnings, errors, messages*/
.messageStackWarning, .messageStackError, .messageStackSuccess, .messageStackCaution {
	line-height: 1.8em;
	padding: 0.2em;
	border: 1px solid #9a9a9a;
	}

.messageStackWarning, .messageStackError {
	background-color: #ff0000;
	color: #ffffff;
	}

.messageStackSuccess {
	background-color: #99FF99;
	color: #000000;
	}

.messageStackCaution {
	background-color: #FFFF66;
	color: #000000;
	}

/*wrappers - page or section containers*/
#mainWrapper {
	text-align: left;
	width: 980px;
	vertical-align: top;
	background-image: url(../images/bg.jpg);
	border: white solid 12px;
    }

#headerWrapper, #contentMainWrapper, #logoWrapper, #cartBoxListWrapper, #ezPageBoxList, #cartBoxListWrapper ul, #ezPageBoxList ul, #mainWrapper, #popupAdditionalImage, #popupImage {
	margin: 0em;
	padding: 0em;
	}

#mainWrapper {
	margin: auto;
	}

#navColumnOneWrapper {
 margin-left:10px;
}

#navColumnTwoWrapper {
	margin-right: 10px;
	}

#tagline {
	color:#000000;
	font-size: 2em;
	text-align : center;
	vertical-align: middle;
	}

#sendSpendWrapper {
	border: 1px solid #cacaca;
	float: right;
	margin: 0em 0em 1em 1em;
	}

.floatingBox, #accountLinksWrapper, #sendSpendWrapper, #checkoutShipto, #checkoutBillto, #navEZPagesTOCWrapper {
	margin: 0;
	width: 47%;
	}

.wrapperAttribsOptions {
	margin: 0.3em 0em;
	}

/*navigation*/

.navSplitPagesResult {}
.navSplitPagesLinks {}

.navNextPrevCounter {
	margin: 0em;
	font-size: 0.9em;
	}
.navNextPrevList {
	display: inline;
	white-space: nowrap;
	margin: 0;
	padding: 0.5em 0em;
	list-style-type: none;
	}

#navMainWrapper, #navCatTabsWrapper {
	background-image: url(http://www.clipcropcrafts.co.uk/includes/templates/template_default/images/top.gif);
	padding: 8px;
	font-family:Arial, Helvetica, sans-serif;
	font-size:8pt;
	font-weight: bold;
	color: #ffffff;
	height: 24px;
	}

#navSuppWrapper {
	background-image: url(http://www.clipcropcrafts.co.uk/includes/templates/template_default/images/top.gif);
	padding: 8px;
	font-family:Arial, Helvetica, sans-serif;
	font-size:8pt;
	font-weight: bold;
	color: #ffffff;
	height: 24px;
}

#navCatTabsWrapper {
	background-color: #ffffff;
	color: #9a9a9a;
}

#navMain ul, #navSupp ul, #navCatTabs ul {
	margin: 0;
	padding: 0.5em 0em;
	list-style-type: none;
	text-align: center;
	line-height: 1.5em;
	}

#navMain ul li, #navSupp ul li, #navCatTabs ul li {
	display: inline;
	}

#navMain ul li a, #navSupp ul li a, #navCatTabs ul li a {
	text-decoration: none;
	padding: 0em 0.5em;
	margin: 0;
	color: #ffffff;
	white-space: nowrap;
	}

#navCatTabs ul li a {
	color: #9a9a9a;
	}

#navEZPagesTOCWrapper {
	font-weight: bold;
	float: right;
	height: 1%;
	border: 1px solid #9a9a9a;
	}

#navEZPagesTOC ul {
	margin: 0;
	padding: 0.5em 0em;
	list-style-type: none;
	line-height: 1.5em;
	}

#navEZPagesTOC ul li {
	white-space: nowrap;
	}

#navEZPagesTOC ul li a {
	padding: 0em 0.5em;
	margin: 0;
	}

#navCategoryIcon, .buttonRow, #indexProductListCatDescription {
	margin: 0.5em;
	}

#navMainSearch {
	float: right;
	}

#navBreadCrumb {
	padding: 0.5em 0.5em;
	background-color: #ffffff;
	font-size: 0.95em;
	font-weight: bold;
	margin: 0em;
	}

#navEZPagesTop {
	background-color: #abbbd3;
	background-image: url(http://www.clipcropcrafts.co.uk/templates/template_default/images/blockdefault2.gif);
	font-size: 0.95em;
	font-weight: bold;
	margin: 0em;
	padding: 0.5em;
	}


#navColumnOne, #navColumnTwo {
	background-color: transparent;
	}



/*The main content classes*/
#contentColumnMain, #navColumnOne, #navColumnTwo, .centerBoxContents, .specialsListBoxContents, .categoryListBoxContents, .additionalImages, .centerBoxContentsSpecials, .centerBoxContentsAlsoPurch, .centerBoxContentsFeatured, .centerBoxContentsNew, .alert {
	vertical-align: top;
	}

/*.content,*/ #productDescription, .shippingEstimatorWrapper {
	/*font-size: 1.2em;*/
	padding: 0.5em;
	}

.alert {
	color: #FF0000;
	margin-left: 0.5em;
	}
.advisory {}
.important {
	font-weight: bold;
	}
.notice {}
.rating{}
.gvBal {
	float: right;
	}
.centerColumn, #bannerOne, #bannerTwo, #bannerThree, #bannerFour, #bannerFive, #bannerSix {
	padding: 0.8em;
	}

.smallText, #siteinfoLegal, #siteinfoCredits, #siteinfoStatus, #siteinfoIP {
	font-size: 0.9em;
	}

/*Shopping Cart Display*/
#cartAdd {
	float: right;
	text-align: center;
	margin: 1em;
	border: 1px solid #000000;
	padding: 1em;
	}

.tableHeading TH {
	border-bottom: 1px solid #9a9a9a;
	}

.tableHeading, #cartSubTotal {
	background-color: #e9e9e9;
	 }

#cartSubTotal {
	border-top: 1px solid #cccccc;
	font-weight: bold;
	text-align: right;
	line-height: 2.2em;
	padding-right: 2.5em;
	}

.tableRow, .tableHeading, #cartSubTotal {
	height: 2.2em;
	}

.cartProductDisplay, .cartUnitDisplay, .cartTotalDisplay, .cartRemoveItemDisplay, .cartQuantityUpdate, .cartQuantity, #cartInstructionsDisplay, .cartTotalsDisplay {
	padding: 0.5em 0em;
	}

.cartUnitDisplay, .cartTotalDisplay {
	text-align: right;
	padding-right: 0.2em;
	}

#scUpdateQuantity {
	width: 2em;
	}

.cartQuantity {
	width: 4.7em;
	}

.cartNewItem {
	color: #33CC33;
	position: relative;  /*do not remove-fixes stupid IEbug*/
	}

.cartOldItem {
	color: #660099;
	position: relative;  /*do not remove-fixes stupid IEbug*/
	}

.cartBoxTotal {
	text-align: right;
	font-weight: bold;
	}

.cartRemoveItemDisplay {
	width: 3.5em;
	}

.cartAttribsList {
	margin-left: 1em;
	}

#mediaManager {
	width: 50%;
	margin: 0.2em;
	padding: 0.5em;
	background-color: #E4FEf5;
	border: 1px solid #003D00;
	}

.normalprice, .productSpecialPriceSale {
	text-decoration: line-through;
	}

.productSpecialPrice, .productSalePrice, .productSpecialPriceSale, .productPriceDiscount {
	color: #ff0000;
	}

.orderHistList {
	margin: 1em;
	padding: 0.2em 0em;
	list-style-type: none;
	}

#cartBoxListWrapper ul, #ezPageBoxList ul {
	list-style-type: none;
	}

#cartBoxListWrapper li, #ezPageBoxList li, .cartBoxTotal {
	margin: 0;
	padding: 0.2em 0em;
	}

#cartBoxEmpty, #cartBoxVoucherBalance {
	font-weight: bold;
	}

.totalBox {
	width: 5.5em;
	text-align: right;
	padding: 0.2em;
	}

.lineTitle, .amount {
	text-align: right;
	padding: 0.2em;
	}

.amount {
	width: 5.5em;
	}

/*Image Display*/
#productMainImage, #reviewsInfoDefaultProductImage, #productReviewsDefaultProductImage, #reviewWriteMainImage {
	margin: 0em 1em 1em 0em ;
	}

.categoryIcon {}

#cartImage {
	margin: 0.5em 1em;
	}

/*Attributes*/
.attribImg {
	width: 20%;
	margin: 0.3em 0em;
}

.attributesComments {}

/*list box contents*/
.centerBoxContents, .specialsListBoxContents, .categoryListBoxContents, .additionalImages, .centerBoxContentsSpecials, .centerBoxContentsAlsoPurch, .centerBoxContentsFeatured, .centerBoxContentsNew {
	margin: 1em 0em;
	}

.centerBoxWrapper {
	border: 1px solid #9a9a9a;
	background: white;
	height: 1%;
	margin-bottom: 1.5em;
	}

h2.centerBoxHeading {
	font-size: 1.3em;
	color: #ffffff;
	}

/*sideboxes*/

h3.leftBoxHeading, h3.leftBoxHeading a,
h3.rightBoxHeading, h3.rightBoxHeading a {
	font-size: 1em;
	color: #ffffff;
	}
#manufacturersHeading, #currenciesHeading, #musicgenresHeading, #recordcompaniesHeading, #searchHeading, #search-headerHeading {
	font-size: 0.9em;
	color: #ffffff;
}

.leftBoxHeading, .rightBoxHeading {
	margin: 0em;
	background-color: #abbbd3;
	background-image: url(../images/tile_back.gif);
	padding: 0.5em 0.2em;
	}

.centerBoxHeading {
	margin: 0em;
	background-color: #abbbd3;
	background-image: url(../images/tile_back.gif);
	padding: 0.5em 0.2em;
}

.leftBoxContainer, .rightBoxContainer {
	margin-bottom: 1.5em;
	}

.sideBoxContent {
	background-color: #ffffff;
	padding:12px 4px;
	}

h3.leftBoxHeading a:hover, h3.rightBoxHeading a:hover {
	color: #FFFF33;
	text-decoration: none;
	}

.rightBoxHeading a:visited, .leftBoxHeading a:visited, .centerBoxHeading a:visited {
	color: #FFFFFF;
	}

.centeredContent, TH, #cartEmptyText, #cartBoxGVButton, #cartBoxEmpty, #cartBoxVoucherBalance, #navCatTabsWrapper, #navEZPageNextPrev, #bannerOne, #bannerTwo, #bannerThree, #bannerFour, #bannerFive, #bannerSix, #siteinfoLegal, #siteinfoCredits, #siteinfoStatus, #siteinfoIP, .center, .cartRemoveItemDisplay, .cartQuantityUpdate, .cartQuantity, .cartTotalsDisplay, #cartBoxGVBalance, .leftBoxHeading, .centerBoxHeading,.rightBoxHeading, .productListing-data, .accountQuantityDisplay, .ratingRow, LABEL#textAreaReviews, #productMainImage, #reviewsInfoDefaultProductImage, #productReviewsDefaultProductImage, #reviewWriteMainImage, .centerBoxContents, .specialsListBoxContents, .categoryListBoxContents, .additionalImages, .centerBoxContentsSpecials, .centerBoxContentsAlsoPurch, .centerBoxContentsFeatured, .centerBoxContentsNew, .gvBal, .attribImg {
	text-align: center;
	}

#bestsellers .wrapper {
	margin: 0em 0em 0em 1.5em;
	}

#bestsellers ol {
	padding: 0;
	margin-left: 1.1em;
	}

#bestsellers li {
	padding: 0;
	margin: 0.3em 0em 0.3em 0em;
	}

#bannerboxHeading {
	background-color: #0000CC;
}

#upProductsHeading {
	text-align: left;
	}

#upDateHeading {
	text-align: right;
	}

/* categories box parent and child categories */
A.category-top, A.category-top:visited {
	color: #fuchsia;
	text-decoration: none;
	}
A.category-links, A.category-links:visited {
	color: #fuchsia;
	text-decoration: none;
	}
A.category-subs, A.category-products, A.category-subs:visited, A.category-products:hover {
	color: #000000;
	text-decoration: none;
	}
SPAN.category-subs-parent {
	font-weight: bold;
	}
SPAN.category-subs-selected {
	font-weight: bold;
	color:fuchsia;
	}
/* end categories box links */

/*misc*/
.back {
	float: left;
	}

.forward, #shoppingCartDefault #PPECbutton {
	float: right;
	}

.bold {
	font-weight: bold;
	}

.rowOdd {
	background-color: #E8E8E8;
	height: 1.5em;
	vertical-align: top;
	}

.rowEven {
	background-color: #F0F0F0;
	height: 1.5em;
	vertical-align: top;
	}

.hiddenField {
	display: none;
}
.visibleField {
	display: inline;
}

CAPTION {
	/*display: none;*/
	}

#myAccountGen li, #myAccountNotify li {
	margin: 0;
	}

.accountTotalDisplay, .accountTaxDisplay {
	width: 20%;
	text-align: right;
	/*vertical-align: top*/
	}

.accountQuantityDisplay {
	width: 10%;
	vertical-align: top
	}

TR.tableHeading {
	background-color: #cacaca;
	height: 2em;
	}

.productListing-rowheading {
	background-color: #abbbd3;
	background-image: url(../images/tile_back.gif);
	height: 2em;
	color: #FFFFFF;
	}

#siteMapList {
	width: 90%;
	float: right;
	}

.ratingRow {
	margin: 1em 0em 1.5em 0em;
	}

LABEL#textAreaReviews {
	font-weight: normal;
	margin: 1em 0em;
	}

#popupShippingEstimator, #popupSearchHelp, #popupAdditionalImage, #popupImage, #popupCVVHelp, #popupCouponHelp, #popupAtrribsQuantityPricesHelp, #infoShoppingCart {
	background-color: #ffffff;
	}
Hope this helps...