IE is displaying my cart to the left of the screen, but looks fine in firfox and safari

I was using bare bones and i made the layout smaller and made some changes recently to the mainwrapper...do u see what could be wrong? - Thanks


/*wrappers - page or section containers*/
#mainWrapper {

background-image: url(transparent);
background-repeat: repeat-x;
background-color: #ffffff;
height:1300px;
position:absolute; "When i add the center value, it makes IE look good, but not firefox and safari.
top:50%;
left:50%;
margin-top:-450px;
margin-left:-430px;
border:10px solid #aaa;
text-align: left;
width: 60%;
border: 1px solid #ccc;
}


}

#logoWrapper{
background-image: url(http://www.mylogo.com/images/thelogo.gif);
background-position: center;
background-repeat: no-repeat;
background-color: #A50000;
height:220px;

}