I've been using QCAD (not very frequent user, only occasionally).
I just upgraded to 2.2.2, because 2.2.0 didn't allow me to change the printing
line thickness. 2.2.2 can do that and I'm happy about it.
However, I found everytime when file dialog opened, QCAD crashes on my Mac.
My Mac 10.5.6, 1.83Ghz/2GB RAM.
Both crashes when open file dialog for "Open file" and "Save as..".
Some time it opens file dialog anyway but doesn't display any list of files and then not responding for ages. (then force quit)
I can open recent files directly under File menu. Double clicking dxf file from Finder opens the file OK.
So File open dialog seems only the problem.
Mac OS X 10.5.6m 1.83Ghz/2GB, QCAD2.2.2