Read-only snapshot problem with service name

I am trying to create a read-only snapshot, using the following commands:

SQL > create database link austin connect to janolav identified by janolav using 'austin';
SQL > create snapshot test as select * from test_at_austin;

giving the error message ORA-12154: TNS:could not resolve service name.

I am, however, able to connect to the other database using the same service name from
SQL*Plus : SQL> connect janolav/janolav_at_austin

so the tnsnames.ora file seems to be OK ?

Am I missing out something fundamental here ?. The machine is a Solaris-box
running 7.3.2.3.0, with the distributed and advanced replication options installed.
The remote machine is an NT, running 7.2. Creating a snapshot on the NT against
a master table on the Solaris machine works fine. -

Any help greatly appreciated!

--
Jan-Olav Eide                    Research Scientist
Norwegian Computing Center       Phone : 22852646, Fax : 22697660
Gaustadalléen 23, P.O Box 114    Email : Jan.Olav.Eide_at_nr.no
Blindern, 0314 Oslo, Norway      http://www.nr.no/home/janolav/joe.html