Hmm.
My first suggestion would be to get some new codecs. Assuming you're exhibiting no other issues, you probably have a bad codec somewhere.
So, in order, I'd do the following:
1) Go here: http://home.hccnet.nl/h.edskes/finalbuilds.htm and get one of the K-Lite Codec Packs.
2) Since you're having stream issues, and many sites use Flash to stream, hit the adobe site and check that your Flash and Shockwave installs are okay.
3) Reinstall your video drivers.
Edited for comprehensibility.
My first suggestion would be to get some new codecs. Assuming you're exhibiting no other issues, you probably have a bad codec somewhere.
So, in order, I'd do the following:
1) Go here: http://home.hccnet.nl/h.edskes/finalbuilds.htm and get one of the K-Lite Codec Packs.
2) Since you're having stream issues, and many sites use Flash to stream, hit the adobe site and check that your Flash and Shockwave installs are okay.
3) Reinstall your video drivers.
Edited for comprehensibility.