I don't know, I never played with the settings a lot. I think it's designed to be a totally automatic thing.
Yeah, thats the impression I got. Thanks.
As for ClamXAV - it's works great for picking up threats, but doesn't have definitions for any OS X malware, so it can't detect them.
The only exception is the OSX.RSPlug.A trojan, which is from late 2007. Versions B, C, D, and E are not detected.