it only happens sometimes.. i dont know why.. ill try to check more about the "surroundings" next time it happens (e.g. whats open, what I did before it happened, etc.)
My aunt's computer did that a few days ago. She dosen't have AIM open ever. ... Trying to remember what I did to fix it. I know I cleared all the cookies, all files & offline files, clear the index.dat file, history, and all auto content. If you have a newer version of norton it will pick up adware/spyware. After I tried to close the first window it started opening a bunch of them and didn't stop. So I just put the cable modem and then did all the stuff I listed before.