My playlist won't show the moodbar for MP3 tracks, just OGG. Any ideas? (I'll post more information, like version number etc, later, now I don't have time)

Ok... I'm using Amarok 1.4.8 (Using KDE 3.5.8-19.fc8 Fedora), and the engine is xine.
The moodbar page in the wiki says that the ffmpeg plugin has problems with mp3, but I don't know what's this ffmpeg or how to change it in the case I use it. My Amarok plays mp3 normally.

Usually moodbar not showing for a particular file type indicates a missing gstreamer plugin - the wiki page tells you how to install these, and which ones you'll need for mp3 - off the top of my head it will involve installing gst-plugins-ugly or something similar. Check your distro repositories for something like that.