I'm having a strange problem with Quicktime 5 on Win XP. I can play videos just fine after starting up my computer. But after a few hours of computer use, if I try to load a quicktime video, the entire quicktime window is transparent. If i go up to the menu, parts of it reappear but not all parts. The video is invisible. The buttons are functional but are invisible. I'm not sure what is causing this. If I reboot, I can use it again like normal, but after a while it starts doing it again. Any ideas? I've already tried reinstalling it.