Playing mp3s in Flash plugin

[jjk7288]

I've got all my codecs downloaded - I can play mp3s in Rhythmbox and other audio players without issue, but Flash mp3 players in particular don't work for me. Their download progress fills to 100%, then they simply don't play.

Any ideas to get this working?

I'm using the proprietary Adobe plugin in Firefox 3 Beta 5 if that helps at all.

EDIT:

It appears that a log out fixed my problem. This must be happening regularly, as I've experienced a similar problem where youtube videos won't play either, and a log out has fixed that. What could be causing this, and how can I fix it so I don't need to log out? :-/