I need help on this issue ASAP ...

Our linux server got recycled yesterday. We have 3 Oracle 10g databases and 3 Oracle 9.2.0.8 databases on that server. The server and databases were brought up fine. The issue we are having is that the db links seem to be broken. If I set my environment to Oracle 10g I can connect (sqlplus) to the mainframe database with no issues. But if I set my environment of Oracle 9.2.0.8 I am not able to make a sqlplus connection to the mainframe database, it gives me a ORA-12154 error. I am sure this is a reason my db links might be broken.
I am able to successfully tnsping to the mainframe environment under both the versions of Oracle.

Please help!!!

Chintz