I have a bookmark containing 12 songs which I have found if I keep pressing the Next track button to get to the track I want, it will end-up sticking on one particullar track and not move on when Next is pressed.

I have rebuilt my database and also tried this in Randomize and Maintain Track Order mode and it happens in both. In Randomize mode it is slightly better as you can press the previous track button once and it will then move on again.

If you let the track finish each time (which can be simulated by pressing and holding the Next button to fast-forward the track) it will unstick itself and move onto the next track.

As a bit of an easter egg, by franticallly clicking the next button you can turn the album cover white (don't know if this is deliberate?)