Hi, have seen a similar error to this but with an earlier version of amarock and the solution was to upgrade - therefore this is not a solution for me !
Running amarok 1.4.1-3fc6 (rpm) on Fedora core 5 with KDE 3.5.2 and qt 1:3.3.6-5@i386.
According to the Fedora forum this should not happen.

I am using the Xine engine.

Have filed bug via email so any input you experts out there ?