[trunk] Copy n' Paste of notes changes flats to sharps

Setup: rev. 4265; Ubuntu 11.04, Qt SDK 1.1 (Qt lib 4.7.3), but the issue occurs also under other OSes.

Steps:

1) Open the attached sample score
2) Select and copy (^C) the whole Flute part
3) Select the first Violin measure
4) Paste (^P) the copied notes into the Violin part

Result: All flatted notes are enharmonically converted to sharped notes.

I tried to follow what happens in function Score::pasteStaff() (file cmd.cpp), but I could not find any obvious problem.

Priority set to critical, as the corrupted notes are often difficult to spot in real scores.

M.