Created attachment 62162 [details]
Terminal output snippet from running amarok --debug

Version:           4.5.0 (using KDE 4.6.5) 
OS:                Linux

Kubuntu 11.04, KDE 4.6.5 packages from Kubuntu PPAs. Amarok is of package version 2:2.4.1-1ubuntu1~natty1~ppa2, Phonon 4:4.7.0really4.5.0-0ubuntu3 and phonon-backend-gstreamer 4:4.7.0really4.5.0-0ubuntu2.1.

When transitioning from one playing FLAC track to another, such as by double-clicking a different track in your playlist or by simply hitting the Next button, Amarok will fail to play the track you're attempting to transition to. It will instead go down your playlist, and (mostly) successfully start to play the following track. This only seems to happen with FLAC tracks, and only with the GStreamer backend.

Reproducible: Always

Steps to Reproduce:
1. Enable the GStreamer Phonon backend
2. Open Amarok
3. Queue at least three FLAC tracks
4. Start playing track 1
5. While playing track 1 (without pausing), change to track 2

Actual Results:  
6. Track 2 is skipped with errors output to the terminal if run with --debug
7. Track 3 starts playing instead

Expected Results:  
6. It should successfully transition into playing track 2

I'm attaching some --debug output that shows when (but not why) it skips the second track. Hopefully the filenames should make it easy to parse what's happening. The interesting bit starts at line ~395.

Noteworthy is that if you let first track end (or merely pausing), it will transition to the next without errors. It only happens when it tries to start playing a FLAC track when something else is already playing.

(Additionally I've managed to get Amarok to hang and soar to 100% cpu use when changing between FLAC tracks like this, but that might be unrelated.)