iFrame? anyway to get rid of it?
iFrames are for images and videos, so no. this iFrame may have been hijacked though.
Mods, check the coding for the site and see if the iFrame(s) are working right.
if it isn't an iFrame, it is probably a Coolwebsearch.com (don't visit that site!!!!!) cookie, which hijacks your web browser. this may also explain why it only affects IE and not FF, if only IE is infected. try the free Trend Micro CWShredder (search trendmicro.com) to fix it.
you could also try running a virus scan, but it might not find the coolwebsearch cookie.