Apple systems have always used different key combinations to perform different tasks, just like all computer makers. However, finding those key combinations has always been an arduous task – they don’t come right out and tell you in the manual how to do some of these.
Bug #872454 in akonadi (Ubuntu): “akonadi complains about invalid maildir after fresh install”
Bug #883604 in qapt (Ubuntu): “QApt GStreamer installer can only find Element Caps (Elements fail)”
check if this is in relnotes in maverick/propose if not