Streaming video help

If someone could help me with this issue I would be most grateful.

At present I am unable to view streaming video (flash, quicktime etc) in any of my internet browsers. When I try to view a video it plays the first two seconds without sound and then stops. I do wait for the video to buffer so that is not the problem.

I have tried reinstalling flash player, deleting preferences, reinstalling my browsers, repairing disk permissions etc.

How can I fix this problem? Everything was working fine a week ago.

ibook g4 1.42 ghz ppc
1gb ram

 

Yep it plays fine when i drag a video into the browser