usermin - ambiguous error when user quota reached

today a user reached is quota and usermin was giving this error:
An error occurred listing mail in this folder : Failed to login to POP3 server : Internal error occurred. Refer to server log for more information. [2008-01-08 12:43:35]

Dovecot was reporting this:
dovecot: Jan 08 12:43:35 Error: IMAP( write_full(/home/ failed: Disc quota exceeded

is it possible to make usermin aware when quota is reached and report it correctly?