Cubase 6.0.3 (running 32bit), OS X 10.7.1 (11B26)
Opening the GUI of Korg M1 Version 1.6.4 (which is the newest available to this date) via the Edit Instrument-Function causes the OS X Menu Bar to change from
Apple - Cubase - File - Edit - etc.
Apple - Cubase - Cubase - File - Edit - etc.
Reproducible - always, remains until restart of Cubase.