No such database

Dear All,

I am new to pgAdmin, running v9.1 on Windows Vista (much to my dismay).

I am trying to set up a connection to a public server at flybase.org, the
details of which are listed at
http://gmod.org/wiki/Public_Chado_Databasesunder "direct chado
access". Using any of the settings for "maintenance DB"
in the drop-down menu I get the error:

"Error connecting to the server: ERROR: No such database: postgres" (or
template1 or whatever).

Does this mean one can only connect to a public database if it is "set up"
for pgAdmin on the server side or is there a different mode of connection
which doesn't involve a "maintenance DB"?

Apologies in advance if I have missed something obvious in the
documentation.

Thanks,

Scott