I can't see much of a problem except that there is a gap in the side borders above the footer in IE7.
This is because you have used a dummy #footer div there which has a line-height and shows the space as a gap. You shouldn't use an id twice on a page, so I used a separate clearer div with no line-height which forms an invisible barrier below the floated divs above:-
</div><!-- rightSide ends here -->
<!--<div id="footer"></div>deleted--> <!--dummy footer ends here -->
<div style="clear: both; width: 100%; height: 0; line-height: 0;
font-size: 0;"> </div>
</div><!-- content ends here -->
Code downloaded to my PC will be deleted in due course.
WIN7; IE9, Firefox, Opera, Chrome and Safari for Windows; screen resolution usually 1366*768.
Also IE6 on W98 with 800*600 and IE8 on Vista 1440*900.