Access level problem on gnats 4.0

I've just installed gnats 4.0 and I'm having a problem getting access to 
a database. This is a single machine (RH7.2), single-user trial setup, 
using gnatsd. 'host_access' contains:

localhost:admin:
*:listdb:

query-pr gives me an 'acess denied' message, and USER says that my 
access level is 'listdb'. If I remove the '*:listdb:' entry then I don't 
get any permissions at all. I've tried variations on 'localhost', and 
tried 'edit' instead of 'admin', but nothing gives me an access level 
above listdb.

I've also tried creating a 'user_access' which contains the single line

evan::admin

but this doesn't make any difference. I know that gnatsd is successfully 
restaring because removing the '*:listdb:' line lowers the permissions.

Any ideas?

Thanks -

Evan