Problem with av_scanner cmdline regular expression

Hello,

In my Exim configuration I have:

  av_scanner = cmdline:/usr/local/uvscan/uvscan --noboot --summary -r -v
--secure --unzip:Found:Found\: (.*)

In an older version of Exiscan the matchrule was:

  exiscan_av_scanner_regexp_trigger = Found
  exiscan_av_scanner_regexp_description = Found:* (.*)$

With the current ac_scanner line I get the error:

  malware acl condition: regular expression error in 'NULL': \ at end of
pattern at offset 6

If I reduce the name regular expression to just (.*) the error goes away,
but ofcourse it will never match :-)

I would expect the default escape character to work, I can't find any
documentation that shows otherwise.

The Exim version:
[root@localhost exim]# exim -bV
Exim version 4.43 #1 built 05-Jan-2005 10:54:04
Copyright (c) University of Cambridge 2004
Berkeley DB: Sleepycat Software: Berkeley DB 4.2.52: (September 21, 2004)
Support for: iconv() IPv6 PAM Perl TCPwrappers OpenSSL
Lookups: lsearch wildlsearch nwildlsearch iplsearch cdb dbm dbmnz dnsdb
dsearch ldap ldapdn ldapm nis nis0 nisplus passwd
Authenticators: cram_md5 cyrus_sasl plaintext spa
Routers: accept dnslookup ipliteral manualroute queryprogram redirect
Transports: appendfile/maildir/mailstore/mbx autoreply lmtp pipe smtp
Fixed never_users: 0
Contains exiscan-acl patch revision 28 (c) Tom Kistner
[http://duncanthrax.net/exiscan/]
Configuration file is /etc/exim/exim.conf

Thank you,
Bas