I'm using the free version of ZA. Together with the application "Phoner" or "Phoner Lite" (a good VoIP App) I get sometimes a blue screen (direct after dialing). I need about 20-25 tries to reproduce this. After deinstallation (deactivation is not enough), it works. I've talked with developer and he told me, that a blue screen can not caused by his application, because he is using APIs and not device drivers. In my opinion a blue screen is a showstopper :-)