Sonetimes no sound on video news

Win MP 7 - Sometimes I get sound on video such as when playing a site like this http://www.hispeed.rogers.com/news/cbcvideo.jsp and after a whiile it won't have sound. Maybe the next day. If my pc is off and I'm powering it up I can tell right away by the startup wav file whether the sound will work on video, if it breaks apart near the end of the wav file then it's 100% that it won't work. A restart seldome helps, a shutdown and a power on works most of the time, sometimes I'll need to do a shutdown a couple of times before it works. MP3 is fine. Wav files usually don't work if I have the problem. Anyone have any suggestions on a fix.

Is there an uninstall program for Windows Media Player 7?
Before I ran adaware and spybot etc the sound with WMP 9 was jumpy. Maybe I should try 9 now that my PC is clean.

Thx in advance.