[Exim] exiscan trouble

Hi !

I use exiscan to check mail for viruses and spam
it worked well but a few days ago it stopped virus checking with kavdaemon
configuration not changed
spam check is ok

here is exiscan config:

exiscan_condition = \
                 ${if or {{eq{$received_protocol}{esmtp}} \
                          {eq{$received_protocol}{asmtp}}  \
                          {eq{$received_protocol}{smtp}}} \
                             {1}{0} }

exiscan_timeout =       5m
exiscan_crypt_salt      =       fo
exiscan_av_condition    =       1
exiscan_av_scanner      =       kavdaemon
exiscan_av_kavdaemon_socket     =       /var/run/AvpCtl

here is exim -bd -d output:

using ACL "check_message"
processing "accept"
accept: condition test succeeded
calling exiscan(); timeout=300
exiscan: starting
exiscan_cleanup(): unlinking
/var/spool/exim/scan/18InUq-000JF8-00/18InUq-000JF8-00-complete
exiscan_cleanup(): unlinking /var/spool/exim/scan/18InUq-000JF8-00/textfile0
exiscan_cleanup(): unlinking /var/spool/exim/scan/18InUq-000JF8-00/textfile1
exiscan_cleanup(): unlinking /var/spool/exim/scan/18InUq-000JF8-00/eicar.com
exiscan_cleanup(): unlinking /var/spool/exim/scan/18InUq-000JF8-00/textfile2
exiscan() returned 0 [message processed ok]
calling local_scan(); timeout=300
local_scan() returned 0 NULL

if i setup to check for spam it works
what the problem?