I also have never gotten Amarok to work very well. I have a collection of 4000 songs (about 20Gb), made up of mp3.ogg and wma files. Amarok alway runs slowly, and the interface freezes for minutes on end.
I've experienced this on Fedora 5, Fedora 6, and now Mint Bianca KDE.
If any has any tips....
Steve

