problem connecting from another host

Running 7.1.2 on Debian Linux/potato (Intel): I'm trying to connect to the
Postgresql database on machine P from machine A. I can, of course, use the
'fpm' database just fine from machine P. TCPIP has been turned on, along
with debugging. The error log shows:

No pg_hba.conf entry for host abc.de.fg.hij, user fpm, database fpm

while in the pg_hba.conf I have an entry:

host fpm abc.de.fg.hij 255.255.255.255 trust

(Initially it wasn't "trust", but first I want to get *some* connection).

There's probably something really stupid going on here, but I haven't yet
figured it out from the old mailing list items, on-line doc's, or Bruce's
book. Could someone please relieve me of another bit of ignorance?

-frank