[exim] multiple domain alias files and wildcard entries

I have been reading quite a few articles and mail list archives to try
and set up my exim4 server to work with alias files for each domain.
After reading all these sources, I finally came up with the following setup:

domainlist local_domains = @:localhost:dsearch;/etc/mail/virtual
...

# Routers

vdom_aliases:
    driver = redirect
    allow_defer
    allow_fail
    domains = dsearch;/etc/mail/virtual
    data = ${lookup{$local_part}lsearch*{/etc/mail/virtual/$domain}}
    file_transport = address_file
    pipe_transport = address_pipe
    retry_use_local_part

real_local:
...

Then /etc/mail/virtual/koivi.com would look like:

justin:  myusername
greg:    otherusername
...

This all works great. However, when I added an entry like:

*:      yetanother

Now *all* mail to that domain gets delivered to the yetanother mailbox
unless that wildcard line is removed. What am I missing?

TIA