problems with qmail-scanner

Hi

I have installed Clamav and Spamassassin to run with Qmail-scanner. It works
fine when I run the test_installation scripts shipped with qmail-scanner
(all four test emails are handled and delivered correctly), but when I add
it to qmail queue it fails with the following error message:

from smtpd log:
@400000003f55b12524759864 X-Qmail-Scanner-1.16:[dp0110625805074263391]
dp0110625805074263391 exits - try again later...

Anyone got an idea on what could be causing this? I've tried increasing
softlimit up to 20000000. Could it be a permissions problem somewhere? could
I be missing some perl modules? (I'm pretty sure that all are installed)

Essential info:

qmail-smtpd supervise script content:

#!/bin/sh
exec /usr/local/bin/softlimit -m 20000000 \
tcpserver -H -R -x /home/vpopmail/etc/tcp.smtp.cdb \
-u `id -u vpopmail` -g `id -g vpopmail` 0 25 \
/var/qmail/bin/qmail-smtpd ihit.no /home/vpopmail/bin/vchkpw /bin/true 2>&1

tcp.smtp file content:

:allow,QMAILQUEUE="/var/qmail/bin/qmail-scanner-queue.pl"

permissions:

-rwsr-xr-x 1 qmaild qmail 59995 Sep 2 13:46
/var/qmail/bin/qmail-scanner-queue.pl*

qmailscan dir:
drwxr-xr-x 4 qmaild qmail 4096 Sep 2 21:10 qmailscan/

content from qmailscan dir:
-rwxr-xr-x 1 qmaild qmail 90399 Sep 2 20:34 qmail-queue.log*
-rwxr-xr-x 1 qmaild qmail 36 Sep 2 12:32
qmail-scanner-queue-version.txt*
drwxr-xr-x 5 qmaild qmail 4096 Sep 2 11:08 quarantine/
-rw-r----- 1 qmaild nofiles 12288 Sep 2 21:10
quarantine-attachments.db
-rwxr-xr-x 1 qmaild qmail 4277 Sep 2 11:12
quarantine-attachments.txt*
-rwxr-xr-x 1 qmaild qmail 945 Sep 2 20:34 quarantine.log*
lrwxrwxrwx 1 qmaild qmail 31 Sep 2 12:32 viruses ->
/var/spool/qmailscan/quarantine/
lrwxrwxrwx 1 qmaild qmail 35 Sep 2 12:32 viruses.log ->
/var/spool/qmailscan/quarantine.log*
drwxr-xr-x 5 qmaild qmail 4096 Sep 2 11:08 working/

Tips would be appreciated.
Thanks.
- Stu