I'm using dovecot (rc17) in POP3/IMAP server _and_ proxy mode (pgsql backend). Everything works fine but occasionally I get these messages in the log:

dovecot: auth(default): file passdb.c: line 126 (passdb_handle_credentials): assertion failed: (password != NULL) dovecot: auth(default): Raw backtrace: dovecot-auth [0x8062b2b] -> dovecot-auth [0x8062599] -> dovecot-auth [0x805a6ae] -> dovecot-auth [0x805b3b8] -> dovecot-auth [0x8060350] -> dovecot-auth(io_loop_handler_run+0x118) [0x8066458] -> dovecot-auth(io_loop_run+0x28) [0x80658e8] -> dovecot-auth(main+0x78) [0x8057028] -> /lib/libc.so.6(__libc_start_main+0xc6) [0x4007ee36] -> dovecot-auth [0x804f591] dovecot: child 15802 (auth) killed with signal 6

I seems (!) that these messages only appear when someone uses dovecot in in IMAP proxy mode.

As I said before, everything works fine -- even reading emails via IMAP-proxy works.

Chris