[ODBC] Windows NT, ODBC 3.x, problem to connect

Hello folks,

after upgrading to PostgreSQL and PostODBC and Microsoft ODBC to the latest
versions I cannot connect to Postgres anymore.

Versions:
backend: PostgreSQL 6.3.2
Linux 2.0.30
172.16.5.12
user: PostgreSQL 6.30.0245
WinNT WS 4.0 SP3
ODBC 3.5
172.16.4.233

error message:
When i try to create a query (MS-Query) i get the error message:
"Could not connect to the server;
Could not connect to the remote socket."

When I connect via telnet to the server and use psql I can access the
requested database w/o problem.
The pg_hba.conf looks like this:
-----start-----
# first attempt
# allow all hosts from 172.16.4.x access to database test1
host test1 172.16.4.0 255.255.255.0 trust

# second attempt
# allow workstation orion access to all databases
host all 172.16.4.233 255.255.255.255 trust

# desperately seeking connection... in the third attempt
host all 0.0.0.0 0.0.0.0 trust
host all trust
-----end-----

any ideas?

Thnx

Matthias