CSS IE7 not picking up on a margin-top

My login page has me baffled.

I’d customised it and it was looking good, well for some reason, it doesn’t look good in IE7 any more. IE7 is refusing to pick up on the margin-top:113px; line in my custom stylesheet. It’s weird though because it was perfect in IE7 and I’ve not changed anything at all. It’s just started happening itself and for no reason… Maybe someone can see why from the CSS below?

body {
color:#555;
font: 12px arial, sans-serif;
background-color:#d0d0d0;
background-image: url(../images/login-back3.png);
background-repeat:no-repeat;
background-position:top:100px;
}

#mainWrapper {
display:block;
margin-top:113px;
border:none;
background-image: url(../images/login-logo.png);
background-repeat: no-repeat;
text-align: left;
vertical-align:middle;
width: 750px; /* sets the width of the store */
background-color:#fff; /* gives the store a white background */
}

#loginDefault {
width: 650px; /* set the width of the login table */
margin-left:41px;
margin-bottom:45px;
}

#navBreadCrumb {
margin-top:95px;
}

This works in all other browsers and it was working in IE7 too, until this morning when I noticed it wasn't working any more? Weird!

Hmmm, don't know how but somehow margin-top had moved from the body class.... fixed below:

body {
margin-top:113px;
color:#555;
font: 12px arial, sans-serif;
background-color:#d0d0d0;
background-image: url(../images/login-back3.png);
background-repeat:no-repeat;
}

#mainWrapper {
display:block;
border:none;
background-image: url(../images/login-logo.png);
background-repeat: no-repeat;
text-align: left;
width: 750px; /* sets the width of the store */
background-color:#fff; /* gives the store a white background */
}

#loginDefault {
width: 650px; /* set the width of the login table */
margin-left:41px;
margin-bottom:45px;
}

#navBreadCrumb {
margin-top:95px;
}