Can't hear youtube, Nothing has worked.

[jonp]

A few months ago I went to visit Youtube.com and watch some video's, and teh video streamed perfectly, but there was no audio, even though the volume was turned up, my headset was working, and 'Allow Sounds from the internet' was checked. My Itunes and my Windows Media player plays fine, crisp sound. I have looked everywhere to find the solution. I checked all of teh audio opions I could find, and they were all apropriate, and i did teh thing with wavemapper, and that didn't help. It is a problem with Internet Explorer and with Mozilla Firefox...can SOMEOEN help me!?!?!?!