respect to you tube video, it also happens on pc, its not problem of apple per se.

it happens to me, and other people, in linux, xp , and windows.

nobody knows the problem, but also, in some flash that are no video , (games), theres also no sound.

i think it's something changed in flash , and also in the browsers.

iexplore doesnt have that error (no sound, video stop at two seconds), so many times.