Resolution:
This is a bug with Oracle 9.2.0.1

This is the error explaination on the oracle documentation:

ORA-24391 invalid fetch operation
    Cause: Scrollable cursor operation requested with non-scrollable cursor.
    Action: Check if the statement was executed in the scrollable mode. The only acceptable orientation is OCI_FETCH_NEXT that ignores the scroll offset parameter.

If you are using Oracle 9.2.0.1 then this is the problem (ORA-24391)
This was bug fixed with Oracle 9.2.0.2

Bug 2460104      Fixed: 9202
Pro* Precompiler
This problem is introduced in 9.2.0.1.
ORA-24391 may occur for DML statements in precompiled code.
The same code works fine in earlier Oracle releases.

Avoid using Oracle 9.2.0.1 even as a client runtime software for WF Server.
This error does NOT appear with Oracle 8.1.7 or 9.2.0.2+