[exim] Demime_errorlevel Using Clamav and exim

Hello,

I've searched archives without answer to my question, though i'm pretty sure
there is already an answer. If it is the case, please excuse me by
advance...

I get the following error message in logs :
2005-12-06 10:31:40 1EjZAd-0001oN-Bt
H=aannecy-152-1-112-18.w86-200.abo.wanadoo.fr (mdgpto.fr) [86.200.31.18]
F=<toist@???> temporarily rejected after DATA: failed to expand ACL
string "${if >{$demime_errorlevel}{2}{1}{0}}": unknown variable name
"demime_errorlevel"

We are completely overdrowned by Sober U worm, and i wish clamav to block
it...
Installed latest version with success, and completed install by adding in
exim 4.54 :
(at top of file)
av_scanner = clamd:127.0.0.1 3310
(in ACL's)
# ACL that is used after the DATA command
check_message:

# Virus Check
deny message = Ce message contient un encodage MIME incorrect
($demime_reason)
malware = *
condition = ${if >{$demime_errorlevel}{2}{1}{0}}
deny message = Ce message contient un virus ou un script malveillant
($malware_name)
malware = *
deny message = Ce message contient un fichier dont l'extension est interdite
(.$found_extension)
malware = bat:com:pif:prf:scr:vbs
warn message = X-Antivirus-Scanner: Le message a été scanné par l'antivirus
ClamAV.
accept

I know since exim 4.51 demime has been depricated... I suppose there is a
problem using $demime_errorlevel which is probably not the correct syntax...

Any idea on how to solve this problem would be appreciated...

Tdldp