I've uploaded version 1.07-pre-1. It is, as its name might imply, a pre-release version of what will be 1.07. It has a more-functional preference pane, and hopefully will work better for folks having a problem with 1.06.

Between 1.05 and 1.06, I completely rewrote the IMAP protocol and connection handler code. Obviously, there were some bugs in it that I didn't find while testing on my home Macs.

Give 1.07-pre-1 a shot (available here), and either comment on this thread about issues you're having with it, or email me.