Had a similar experience (albeit with much minor consequences): an Oracle Portal installation which worked fine in Dev/Test but with degrading performance on the actual Prod server (which was also immensely more powerful than what we used to develop).
Oracle was called in, "en masse". Keep also in mind that Oracle Portal was basically running on top of lots of dedicated tables and stored procedures and you could not access the data directly, you interacted to the contents only through vistas, aliases etc.
It was indeed due to a smallish version bump.
But we had a pretty good Team Leader who had made Oracle declare that the two different version were absolutely compatible and allowing us to write code on the older version.
He made them state this in written form, before starting the development so it was later impossible to blame the developers for the problem.
Oracle was called in, "en masse". Keep also in mind that Oracle Portal was basically running on top of lots of dedicated tables and stored procedures and you could not access the data directly, you interacted to the contents only through vistas, aliases etc.
It was indeed due to a smallish version bump. But we had a pretty good Team Leader who had made Oracle declare that the two different version were absolutely compatible and allowing us to write code on the older version.
He made them state this in written form, before starting the development so it was later impossible to blame the developers for the problem.