I'm not sure what is causing this issue. But see in the attached image how the left side of the page is nudged inwards.

This appears ONLY in IE7, it looks fine even in IE6!!

Here is a link to the page - http://tinyurl.com/6hal5nm

The page uses the exact same markup as the home page - http://tinyurl.com/6kdu8rx

...apart from where the products are listed anyway. But I even tried removing this section altogether and still the problem was there.

Maybe I'm missing something really obvious and the 14 hours I've spent sat at the computer has fried my brain beyond the point of being able to notice the problem.

But if anyone has any ideas that would be great

In #page #content class, position your background image to left instead of center and try. Hope this solves your problem.

#page #content {
    background: url("../images/content.gif") repeat-y scroll left 0 transparent;
    display: block;
    margin: 0;
    overflow: hidden;
    padding: 5px 0 15px;
    width: 100%;
}

That worked! Thanks a lot, didn't even think of trying that