Jim, it sounded like you were using the ..\sanscreen\backup\backup.cmd file. This generates a .sql dump of the OCI database.This is intended for bare metal restore scenarios for OCI,not for upgrades.
If you have ever looked at the upgrade.log after a restore during an upgrade, you will see all the events from "upgraders" that run after the database was actually restored - these are schema modifications/cleanups/additions. There can also be cleanup upgraders for known bugs. By using the restore.cmd to restore a sql dump, you would not have these upgraders run, meaning you could have OCI 6.x running with a OCI 6.(x-y) database, which can cause havoc as OCI tries to store stuff in tables/columns that do not exist.
I believe if you put the .sql into a zip file, and name it appropriately for the right version, you can then restore that zip through the portal in a newer version.