I installed MPlayer, it's browser plug-in and all other nessessary codecs via Automatix.

I use Firefox. MPlayer doesn't always load the video I'm trying to watch. Totem tries and fails. I've noticed that MPlayer always opens the Windows Media streams, but never does Quicktime (don't know about Real Player, haven't tried yet). And the sound quality is very choppy on the videos MPlayer opens. It may be better in the Quicktime streams, I don't know. How do I make MPlayer the defult browser player and for it to open all three kinds of streams?

I'm using Breezy.

Did you install the essential codecs?

I just did. It's still doing it.