Switching concert pitch between parts confuses the key signature

OS: Mac OS X 10.9.4
MuseScore 2 Beta 1 (1efc609)

1) a score with a transposed instrument, e.g. soprano sax, key is C major, i.e. if concert pitch is off the key signature shows D major
2) add one note, e.g. C (reads a D in concert pitch)
3) Make sure concert pitch is off, then define a part for the saxophone
-> key signature is D major for both score and part

4) turn on concert pitch in the score
-> score shows correctly C major for the sax now, the note is C
5) change to part
-> sax part shows C major, but not is still D. If played back it seems to be correctly C, though.

7) while in sax part turn off concert pitch
-> key signature for the sax voice is now in Bb Major (!), but note is now notated as C, both in part and score.

etc. It seems that key signature and notes are linked to the same concert pitch setting, but not updating correctly in both. I've have the impression that the current setting is somehow saved into a file, and it can be rather tricky to fix the situation later.

Probably the same bug as reported (but marked as fixed) in: http://musescore.org/en/node/29791