Start Internet Explorer with no Add-ons, see if the problem still exists.
Start, All Programs, Accessories, System Tools, Internet Explorer (no Add-ons).
If the problem is gone then start IE normally. Click on Tools then Manage Add-ons and start disabling then a few at a time till you find the one causing the problem.
IE does not need any Add-ons and almost always works better without them. I'd recommend disabling all IE Add-ons except Java (tm) Plug-In SSV Helper and Plug-In 2 SSV Helper. You choice though.