I found just a few more issues/suggestions for this application to become the perfect one:
1. the Zoom key control for tracks is not working - only the volume can be controlled (maybe something wrong on my device?)
2. it would be great if you can also add fast forward/backward support (from the zoom keys for long press also)
3. auto resume playback setting support (when exiting and relaunching application)
4. and A->B repeat playback support - this is most useful when using languages learning audio tracks which i use very often. i haven't seen any audio playback application that supports it for the n900 yet...
5. Track length/skipping bar available also in list view.

This is a great application.
Thanks!