Shopping Cart Table messed up

Hi,
I've done some customizations to the look of my shopping cart table. It looks great in IE, but it's all messed up in Mozilla and Chrome. I could use some help. Here's the code for the table:

<table  border="0" width="100%" cellspacing="0" cellpadding="0" id="cartContentsDisplay">
     <tr class="tableHeading">
        <th scope="col" id="scQuantityHeading"><?php echo TABLE_HEADING_QUANTITY; ?></th>
        <th scope="col" id="scUpdateQuantity"> </th>
        <th scope="col" id="scProductsHeading"><?php echo TABLE_HEADING_PRODUCTS; ?></th>
        <th scope="col" id="scUnitHeading"><?php echo TABLE_HEADING_PRICE; ?></th>
        <th scope="col" id="scTotalHeading"><?php echo TABLE_HEADING_TOTAL; ?></th>
        <th scope="col" id="scRemoveHeading"> </th>
     </tr>
         <!-- Loop through all products /-->

In Mozilla, the headers are just stacked up into one column on top of each other, rather than aligned vertically across the top of the table. In IE, they are aligned horizontaly as I would expect.

If you'd like to see it for yourself, my site is https://www.delightfuldaisy.com, just add a product to your cart and you'll quickly see.

Thanks in advance for any help.

TJ

99.99% of the time, when your page looks good on (browser-x) and doesn't on (browser-y), it's due to validation errors in the generated HTML. In your case, you've got 32 errors and 6 warnings (http://validator.w3.org/check?verbose=1&uri=http%3A%2F%2Fwww.delightfuldaisy.com%2Fshopping_cart) on that page.

Fix the validation errors ... and then check the formatting under FireFox and Chrome again.