Can't change Track Number

Once a track has a number it can't be changed by double-clicking on the field. Let's say it's 1 now, you enter 2 in there and as soon as you hit enter it changes to 1 again. If you specifically click "Edit" on the track and enter a new number in the Track box it'll change when you're back in the playlist view.

A track without a track number can be given any number at first, but will stick to that afterwards until you go into the Edit view to change it.

Not a set-killing biggie but please fix this. Thank you :)