Pentax Optio S4 A90 error

Hello,

I have an Optio S4 digital camera that always boots with the A90 error.
I read that it can be fixed with a firmware upgrade using the "secret
menu". I can access the secret menu and I can see the "ROM UPDATE"
option, but I'm looking for the firmware file. I can get the firmware
file for the S4i version, but no luck finding the firmware for the S4.


Anyone knows where I could download this file? Any help would be
greatly appreciated.

Christian