same here:
Jan 25 18:04:03 web01 qmail-queue-handlers[21345]: SKIP during call 'check-quota' handler
Jan 25 18:14:59 web01 qmail-queue-handlers[22152]: SKIP during call 'check-quota' handler
Jan 25 18:15:53 web01 qmail-queue-handlers[22200]: SKIP during call 'check-quota' handler
Jan 25 18:17:12 web01 qmail-queue-handlers[22270]: SKIP during call 'check-quota' handler
Jan 25 18:20:57 web01 qmail-queue-handlers[22637]: SKIP during call 'check-quota' handler
Jan 25 18:24:13 web01 qmail-queue-handlers[22753]: SKIP during call 'check-quota' handler
Jan 25 18:24:44 web01 qmail-queue-handlers[22791]: SKIP during call 'check-quota' handler
Jan 25 18:25:59 web01 qmail-queue-handlers[22847]: SKIP during call 'check-quota' handler
Jan 25 18:31:29 web01 check-quota filter[26501]: Failed to run '/usr/sbin/postalias -q
user@remotedomain.com hash:/var/spool/postfix/plesk/virtual', rc = 1
Jan 25 18:31:29 web01 /usr/lib/plesk-9.0/psa-pc-remote[26219]: SKIP during call 'check-quota' handler
Jan 25 18:33:52 web01 /usr/lib/plesk-9.0/psa-pc-remote[26219]: SKIP during call 'check-quota' handler
Jan 25 18:35:52 web01 /usr/lib/plesk-9.0/psa-pc-remote[26219]: SKIP during call 'check-quota' handler
Jan 25 18:36:02 web01 /usr/lib/plesk-9.0/psa-pc-remote[26219]: SKIP during call 'check-quota' handler
Jan 25 18:38:32 web01 /usr/lib/plesk-9.0/psa-pc-remote[26219]: SKIP during call 'check-quota' handler
Jan 25 18:43:54 web01 /usr/lib/plesk-9.0/psa-pc-remote[26219]: SKIP during call 'check-quota' handler
Jan 25 18:46:53 web01 check-quota filter[27565]: Failed to run '/usr/sbin/postalias -q
user@remotedomain.com hash:/var/spool/postfix/plesk/virtual', rc = 1
Jan 25 18:46:53 web01 /usr/lib/plesk-9.0/psa-pc-remote[26219]: SKIP during call 'check-quota' handler
Jan 25 18:52:10 web01 /usr/lib/plesk-9.0/psa-pc-remote[26219]: SKIP during call 'check-quota' handler
Jan 25 18:52:31 web01 /usr/lib/plesk-9.0/psa-pc-remote[26219]: SKIP during call 'check-quota' handler
Jan 25 18:54:01 web01 check-quota filter[27787]: Failed to run '/usr/sbin/postalias -q
user@remotedomain.comhash:/var/spool/postfix/plesk/virtual', rc = 1
Jan 25 18:54:01 web01 /usr/lib/plesk-9.0/psa-pc-remote[26219]: SKIP during call 'check-quota' handler
10.4.4 Debian 6.0 1013111102.18