How do I downgrade from os3.5 to os3.3

[AndyHas]

I am trying to downgrade to OS3.3 from OS3.5.0

I tried to revert to 3.3 following the the Palm website instructions.
However I get the following error message after placing Vx in debug mode and folowing instructions.

In debug mode system says:
"error flashing rom into handheld. Existing rom is invalid, entire rom
needs to be re flashed"

I have Palm Vx running 3.5.0.
Vx originally supplied with 3.1..

How can I get back to 3.3.
My data is backed up so I don't care how harsh the solution may be.
::confused:

[DrMud]

I assume that there is an application or interface that you need to access that is not compatable with 3.5, is this correct?
Is the Palm operating normally with 3.5?
Doc