WinMediaPlayer7 crashes playing mpg file

I upgraded form Win 95 to Win 98 and installed a Logitech Webcam Express on my USB port. I upgraded WinMedia Player to version 7 and now it crashes when I play an mpg file which I used to play before these upgrades. Occassionally the file will play fine, but most of the time I get a protection fault in module “unknown”, so I’m not even sure which module is at fault causing my MediaPlayer to crash.