I use texstudio271_snapshot_2014-05-25_win_qt5 + Win8.1 (64bit).
I couldn't type the sign [ (left brace). The default shortcut of Menus/Idefix/Go to/Definition is Ctrl+Alt+F. But in Windows the shortcut Ctrl+Alt is equal to AltGr and the Hungarian keyboard AltGr+F is the sign [. So I had to change the shortcut Ctrl+Alt+F, and then every OK.
But, a simple user doesn't search the reason. So I suggest, should be changed from Ctrl+Alt+F to (for example) Ctrl+Alt+Shift+F (only for Win + Hungarian).
This problem have fixed in #277, but now it cames up again.