My iMac G5 has had this problem already for a little while, and I think it's in need of codecs reinstall. iTunes and QuickTime work normally, but that's about it. RealPlayer and Windows Media Player 9 play video, but without sound. Same goes for their respective browser plugins. I think it happened when I installed Myst V Demo, or when I was playing around with Flip4Mac. I know where the codecs are stored on a Windows machine, but how do I access them/reinstall them? Thanks for any help.

Well, all the codecs are installed in either /Library/Quicktime, or ~/Library/Quicktime.

OK, thanks for that. I'll let you know how it goes.

flip for mac. codecs are in library/quicktime or home/lib/QT. and without
flip4mac you have no wma.

I tried deleting the contents of my /library/quictime and ~/library/qt (after I had made a backup, of course), and tried reinstalling Flip4Mac. No change though.

is it possible that your flip4mac timed out?

YOU ARE A GENIUS!!!! Starting up GarageBand and then closing it restored everything!

I'm totally amazed. :) :) :)

Glad that worked.. what a weird work around for an (still) unknown problem.