All my pages have a master page and I set the following CSS to centre the pages and remove the margins etc:

body
{
margin: 0;
padding: 0;
background: #D0D1D3;
margin: auto;
}
#PageWrapper
{
border-style: none;
border-color: inherit;
border-width: medium;
min-width: 990px;
height: 700px;
text-align: left;
margin-top: 0px;
border: none;
}
#MainContent
{
width: 630px;
min-height: 500px;
float: left;
}


My content place holder is in the MainContent Div. Whats wierd is that all my other pages (except the home page) seem to have a border on the left and so move slightly to the right - but I cant see where this is happening...