Tried the new version and it works fine so far.
Problem now is:
I use 2 displays, it only docks to the main display, but it should dock on the secont monitor.
Also the rightclick-menu opens on display 1 even tought MusicBee is on display 2.
Maybe its possible to choose to dock Miniplayer to the current display?
If that works, the only thing I would miss is an appearance of the miniplayer like windows 7 taskbar... :-D