X-Axis (bed forward or back) Error

[chromii]

Have 2 UP+2 printers which when initialised the Platform 'Creeps' forward instead of back towards the limit switch.
After the Y-Axis zeros on it's limit switch the X-Axis 'Races' forward until it crashes into the end belt roller.
Both printers are running ROM V6.090 & Firmware 3.07.
If I try to reload the ROM file it loads successfully, then reports an error with Firmware read port, I/O port.
Replacing the CPU card with one running ROM V6.07 & Firmware V3.04 works perfect on both printers.

The strange thing is V6.090 was not released to USERS via the Systems Draw in any versions of UP Print.
On of the Printers is one of the 1st UP+2 & I have only ever installed ROM V6.07.

So how did V6.090 get on it & why has the firmware been disabled from being upgraded or downgraded.
I suspect there is a issue with V3.07 firmware & TT just want us to pay for the WiFi upgrade CPU.

Thoughts anyone ?