Looks like a problem with your peerblock.conf file:
[4/7/2010] [20:51:47.781] [03624] [Configuration] [Load] found peerblock configuration file
[4/7/2010] [20:51:47.781] [03624] vvvv EXCEPTION!! vvvv
[4/7/2010] [20:51:47.781] [03624] An uncaught exception occured!
I'm able to reproduce this error myself, using your .conf. Try deleting this file from your machine, and restarting PeerBlock; PeerBlock should then attempt to instead load your peerblock.conf.bak file, hopefully without issue. If that file also causes the app-crash though, delete both peerblock.conf and peerblock.conf.bak and restart PeerBlock. You'll need to re-setup all your options & lists again, but at least PeerBlock will be working for you.
Sorry you were hit by this issue, but thank you for reporting it and including your files! I'm working on patching around this error right now, using your .conf as a "test case", hopefully should be able to better recover from this sort of an error in the next Beta Release.
--- Mark ---
P.S. Also, what issues were you having with r320 that caused you to want to run with r277 instead?
Lead developer of PeerBlock
