Export failed on origin database

While in the Database Cache Configuration Assistant of Oracle9i AS (1.0.2.1.0) I encountered this error:

Adding users to cache failed.
Reason: WTE-03501 Error updating list of users.
Export failed on origin database.

When i read the error logfile produced by the configuration assistant
it contains the following messages:
EXP-00056: ORACLE error 1034 encountered
ORA-01034: ORACLE not available
ORA-27101: shared memory realm does not exist
SVR4 Error: 2: No such file or directory
EXP-00005: all allowable logon attempts failed
EXP-00000: Export terminated unsuccessfully

But my origin database was up and running during the cache configuration. I think this is a problem with setting of ORACLE_HOME.
Ive already set the ORACLE_HOME (right oracle home of origin database) of the user running the Cache Configuration assistant but still it uses the ORACLE_HOME of the 9iAS oracle home. How can i tell the configuration assistant to used the ORACLE_HOME of the origin database?

Thank You.