Error 550 Mailbox unavailable instead of "this message containts malware"

Hi. 
I have found a strange problem and i dont know if it is exiscan or exim
that causes this.
 
I have exim 4.34 with the exiscan patch and use spam and virus checking.
The virus check seems to work , exim doesnt let any virus slip trough,
But. The reply
Is "error 550, mailbox unavailable"  instead of "This message contains
malware" when it finds a virus
In DATA.
The exim_rejectlog says " this message contains malware"
 
First i thought it was some kind of translation in our exchange server.
But telneting to the server
At port 25 and mail from / rcpt to /data 
And the the eicar signature gives me the same . mailbox unavailable.
 
My config has these acl's:
acl_smtp_rcpt = acl_check_rcpt
acl_smtp_data = acl_check_content
 
 
my acl_check_content  looks like this:


acl_check_content:
deny  message = This message contains a MIME error ($demime_reason)
      demime = *
      condition = ${if >{$demime_errorlevel}{2}{1}{0}}
 
# move zips to spambox       
   warn message  = X-Redirect-To:[email protected]
   demime = zip
        
# Reject virus infested messages.
  deny  message = This message contains malware ($malware_name)
  malware = *
 
  warn  message = X-Spam-Score: $spam_score ($spam_bar)
        spam = nobody:true
  warn  message = X-Spam-Report: $spam_report
        spam = nobody:true
 
  
# Redirect spam to spambox
  warn message = X-Redirect-To:[email protected]
  spam = nobody
 
# finally accept all the rest
  accept
  
 
Any clues or suggestions?
 
Regards
Tomas Lubkowitz