Below is some more information and logs from Comodo. In Pegasus I always retrieve only email titles from the server (which allows deleting unwanted messages straight on the server without actually downloading any of them to PC). The following command is used in Pegasus:

http://img44.imageshack.us/img44/650/11082009042545.png

In this case it makes no difference because there were no messagaes on the server.

Comodo Connections Log:

http://img197.imageshack.us/img197/2595/11082009044208.png

Comodo Activity Log after polling POP3 server from Pegasus a few times, Locate32 never started:

http://img44.imageshack.us/img44/9692/11082009042700.png

Comodo Activity Log after Locate32 was started and POP3 server was subsequently polled twice from Pegasus:

http://img194.imageshack.us/img194/9824/11082009043154.png

One possible theory would be that Locate32, when run alongside Comodo Firewall Pro, somehow interferes with "wsock32.dll" used by Pegasus.

I have lately got into some mysterious issue with Comodo Firewall Pro, Pegasus Mail and Locate32 (file search engine).

I've been running Comodo Firewall Pro v2.4.18.184 for two or three years and it has never interfered with Pegasus Mail v4.31. Here are Comodo's network control rules. The only custom lines are for WallWatcher (router traffic/bandwidth monitoring tool):

http://img36.imageshack.us/img36/2137/11072009151900.png

Normally, Pegasus can connect to POP3 server in about a second, using very little system resources:

http://img52.imageshack.us/img52/9969/11072009162230.png

A few days ago I installed Locate32. As soon Locate32 is launched, Pegasus either needs a few seconds to connect to POP3 server, gobbling 100% of system resources while doing so, or is unable to connect at all, and Telnet test fails:

http://img25.imageshack.us/img25/9079/11072009170812.png
http://img97.imageshack.us/img97/3139/11072009142409.png
http://img21.imageshack.us/img21/7384/11072009174000.png

Closing Locate32 doesn't resolve the issue, but if Comodo is closed, the problem disappears, Pegasus works ok and Telnet command is executed successfully:

http://img10.imageshack.us/img10/2668/11072009173832.png

Of course restarting the PC also solves the problem, until Locate32 is launched again. Thanks for suggestions.

( Locate32 can be found here: http://www.locate32.net/ )