Hi all,
I'm trying to configure Postfix with spamassassin. I'm using virtual domains and accounts with mysql database. Everything works OK without the spamassassin. When I try to use it with postfix it gives me an error and I cannot receive e-mails to my virtual accounts.
Here is the /var/log/maillog information, and below I'll paste the config files:

Jan 2 00:36:11 hosting postfix/qmgr[22204]: 57B16D370: from=<root@hosting.megalan.bg>, size=655, nrcpt=1 (queue active)
Jan 2 00:36:11 hosting postfix/qmgr[22204]: B3DC1D365: from=<maravunko@mail.bg>, size=3219, nrcpt=1 (queue active)
Jan 2 00:36:32 hosting postfix/smtpd[22205]: connect from mx1.mail.bg[193.201.172.114]
Jan 2 00:36:32 hosting postfix/smtpd[22205]: DE4229AEC: client=mx1.mail.bg[193.201.172.114]
Jan 2 00:36:32 hosting postfix/cleanup[22212]: DE4229AEC: message-id=<1104618993.62a240e5931f6@mail.bg>
Jan 2 00:36:32 hosting postfix/qmgr[22204]: DE4229AEC: from=<maravunko@mail.bg>, size=3213, nrcpt=1 (queue active)
Jan 2 00:36:32 hosting postfix/smtpd[22205]: disconnect from mx1.mail.bg[193.201.172.114]
Jan 2 00:37:06 hosting spamd[22000]: connection from localhost [127.0.0.1] at port 1062
Jan 2 00:37:06 hosting spamd[22000]: handle_user: unable to find user 'nikolay@zayanelov.com'!
Jan 2 00:37:06 hosting spamd[22000]: processing message <200501012233.j01MX1BG022168@hosting.megalan.bg> for nikolay@zayanelov
.com:995.
Jan 2 00:37:06 hosting spamd[22001]: connection from localhost [127.0.0.1] at port 1063
Jan 2 00:37:06 hosting spamd[22001]: handle_user: unable to find user 'nikolay@zayanelov.com'!
Jan 2 00:37:06 hosting spamd[22001]: processing message <1104618993.62a240e5931f6@mail.bg> for nikolay@zayanelov.com:995.
Jan 2 00:37:06 hosting spamd[22002]: connection from localhost [127.0.0.1] at port 1064
Jan 2 00:37:06 hosting spamd[22002]: handle_user: unable to find user 'nikolay@zayanelov.com'!
Jan 2 00:37:06 hosting spamd[22002]: processing message <1104618881.5d37a108e05b3@mail.bg> for nikolay@zayanelov.com:995.
Jan 2 00:37:06 hosting sendmail[22218]: j01Mb6rf022218: Authentication-Warning: hosting.megalan.bg: spamfilter set sender to
root@hosting.megalan.bg using -f
Jan 2 00:37:06 hosting sendmail[22227]: j01Mb6A9022227: Authentication-Warning: hosting.megalan.bg: spamfilter set sender to
maravunko@mail.bg using -f
Jan 2 00:37:06 hosting sendmail[22226]: j01Mb6hQ022226: Authentication-Warning: hosting.megalan.bg: spamfilter set sender to
maravunko@mail.bg using -f
Jan 2 00:37:07 hosting spamd[22000]: clean message (-1.5/5.0) for nikolay@zayanelov.com:995 in 1.5 seconds, 677 bytes.
Jan 2 00:37:07 hosting spamd[22000]: result: . -1 - ALL_TRUSTED,NO_DNS_FOR_FROM,NO_REAL_NAME scantime=1.5,size=677,mid=<20050
1012233.j01MX1BG022168@hosting.megalan.bg>,autolearn=ham
Jan 2 00:37:07 hosting sendmail[22218]: j01Mb6rf022218: from=root@hosting.megalan.bg, size=890, class=0, nrcpts=1, msgid=<200
501012233.j01MX1BG022168@hosting.megalan.bg>, relay=spamfilter@localhost

and cycles this messages until stop the spamassassin

Here are the non-default variables:
root@hosting:~# postconf -n
alias_maps = hash:/etc/postfix/aliases
command_directory = /usr/sbin
config_directory = /etc/postfix
daemon_directory = /usr/libexec/postfix
debug_peer_level = 2
html_directory = no
mail_owner = postfix
mailq_path = /usr/bin/mailq
manpage_directory = /usr/local/man
mydestination = $myhostname, localhost.$mydomain, localhost
mydomain = megalan.bg
myhostname = hosting.megalan.bg
mynetworks = 127.0.0.0/8
myorigin = $myhostname
newaliases_path = /usr/bin/newaliases
queue_directory = /var/spool/postfix
readme_directory = no
sample_directory = /etc/postfix
sendmail_path = /usr/sbin/sendmail
setgid_group = postdrop
smtpd_recipient_restrictions = permit_mynetworks, check_client_access hash:/etc/postfix/pop-before-smtp, reject_unauth_destination, reject_invalid_hostname
unknown_local_recipient_reject_code = 550
virtual_alias_maps = mysql:/etc/postfix/mysql_virtual_alias_maps.cf
virtual_gid_maps = static:998
virtual_mailbox_base = /home/vmail
virtual_mailbox_domains = mysql:/etc/postfix/mysql_virtual_domains_maps.cf
virtual_mailbox_limit = 51200000
virtual_mailbox_maps = mysql:/etc/postfix/mysql_virtual_mailbox_maps.cf
virtual_minimum_uid = 100
virtual_transport = virtual
virtual_uid_maps = static:998

In master.cf I added:
smtp inet n - n - - smtpd
-o content_filter=spamcheck:

spamcheck unix - n n - - pipe
flags=Rq user=spamfilter argv=/usr/bin/spamfilt ${sender} ${recipient}

spamfilt bash script contains:
#!/bin/sh

sender=$1
shift
recip="$@"
if [ "$#" -eq 1 ]; then
/usr/bin/spamc -u $recip
else
/usr/bin/spamc
fi | /usr/sbin/sendmail -i -f $sender -- $recip
exit $?

This exampe is taken from an O'Reilly book for spamassassin... It should work, but it doesn't.
Also I made tests with spamc -c < sample-nonspam.txt and spamc -c < sample-spam.txt and spamc and spamassassin work.

If you have any idea why it isn't working please help