Window not resizable on Mac OS X
As shown on http://skitch.com/fuzzy76/b7b4s/quassel-irc-quassel the main window starts in a way too small state on OS X and is not resizable.
The client I used was this: http://quassel-irc.org/pub/QuasselClient_MacOSX-universal_0.5-rc1.dmg
Maximizing worked. Later I also discovered that adding the statusbar to the window would also let me resize it.