Even if you are having better luck with Firefox, fact remains you are probably infected with a Trojan.
In Internet Explorer you can, if you wish, set your starting Homepage to a blank page. If you do so, you will get a blank page when you open I.E. and see about:blank in the address bar. This is normal
only if you've set it that way yourself.
If you didn't set I.E. for a blank page then chances are very high that your computer is infected with a trojan. You can find some info on it here:
http://support.microsoft.com/?scid=kb;en-us;894269An excellent program for preventing trojan infections and finding them is Trojan Hunter. They have a free 30 day trial version available that allows a one time only definitions update. I'd suggest you download and install that, update it and scan with it........
after disabling System Restore. Trojans love to hide out in System Restore and continue to reinfect, over and over again. After scanning with Trojan Hunter, and hopefully finding and removing the trojan, you can enable System Restore again.