Cannot add top note to chord

1) Enter g - slightly above upper staff line;
2) try enter note above g (octave higher, for example) but at the same horizontal position;
3) -> no luck to do that (note is added near the first one);
4) but at the bottom notes are added with no prob;
5) after adding note at the bottom everything is ok at the top also - relayouting?

Result on Windows 7 - same as on Linux (Kubuntu 12.10):
//drive.google.com/file/d/0B5alKuFoSol2WjZiTDdycTZueXM/edit?usp=sharing

Master commit: https://github.com/musescore/MuseScore/commit/1cfa9547ba98bd437bb932440…

First commit where this issue appears: https://github.com/musescore/MuseScore/commit/e534cccef8052c0b2b5b67f62…

If change commented/uncommented code here: //github.com/musescore/MuseScore/blob/master/libmscore/chord.cpp#L2426
everything seems to work fine.

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UPDATE: as commented below it happens with mouse input