Not sure if this is a 'bug' per-se, but it's certainly a little annoying.
If I have a track named "artist - track' and I edit the name to just the last half (track) and then hit tab to move to the artist column, in-between the rename and the tab the column re-sorts itself. Which means when the tab moves to the next column it's moving to the WRONG track. I'm sure this has everything to do with what columns are being sorted. But it's a serious UI problem in that the tab movement really isn't valid.
The fix would be to STAY with the track and move to the next column for THAT track, not the one at that place in the displayed list. Or, at the very least, invalidate the tab action such that it didn't drop them into an edit box for a now completely different row.
MC's abilities for doing track edits is really great, I know of nothing better, but it's little UI things like this that make it a bit harder to use that necessary.
That and PLEASE GIVE US A WAY TO TELL THE ACTION BOX TO STOP RAISING ITSELF! Yes, shouting (again, and again...) I hate that damned box and have NO USE FOR IT. Give me an option to cripple it's tendency to pop itself up all the danged time!