My year old MBP isn't playing any streaming videos that are watched online. It will play them for about three seconds, and then the image freezes. There is no audio at any point either. I'm having no trouble using my iTunes, or watching videos saved to my computer through Quicktime. I installed updates, restarted the computer, and tried using both Safari and Firefox - no luck. Any suggestions?

 

If you mean flash movies like youtube and such, chances are good that the flash plugin is borked. Just reinstall it.