[Exim] problem with virtual director

I've got a virtual director which appears to have had a bug for two
years!

here is what it looks like:
====
virtual_localusers:
driver = accept
domains = cdb;virtual_localuser_domains.cdb
condition = \
${lookup{$local_part@$domain}cdb{virtual_localusers.cdb}{yes}{no}}
no_more
transport = virtual_local_delivery

====

the problem is that a name which is NOT in the virtual list sneaks
thru to the next DIRECTOR _if_ it is a real name on my system.

the above DIRECTOR (I assumed) would fail the message with "no_more".
where have I gone wrong? I want this DIRECTOR to be the final test
for one of my virtual domains.
what follows are my normal userforward: and local_users: directors.
the virtual email is sneaking thru into my local_user director.
I know that I could qualify my local_user director with my absolute
local domain names and have a final failing director, but there must
be a way to have the virtual_localusers director fail above.

please help