This is a blind guess...
Check the parameters in the init.ora and try increasing the values for the db_buffer_blocks and shared_pool_size. (stop the DB, edit the file, and start it up again). This assumes you have control of the 7.3.4 Oracle instance.
This is more knowledgable input....
You need to keep in mind that the 9i client may not work with a 7.3.4 database. Oracle did not go out of their way to keep version 7 databases up-to-date. You should be running at least an 8i DB. If yo want to connect to the 7.3.4 database, you may simply be foreced to us an older client - either 8, 8i, or even 9, but NOT 9i.
Fuller Ming, Jr.
Assistant Director, MIS/IT
University of Maryland
Department of Dining Services