>I have forms 6i installed on C:\ and Oracle 9i Databse installed on F:\
By loading two different Oracle products on the same PC,
you have two ORACLE_HOME trees and two TNSNAMES.ORA files.
If/when the TNSNAMES.ORA file under the Forms tree does not contain
an entry for the database, then Forms can't locate the DB;
even though it is right next door.