As posted in the original thread -
Do you have an SAFC ot other piggy back device?
I had a similar problem that turned out to be a problem with the wiring at the ECU plug. (possibly caused when they put in the SAFC)
It was easy to diagnose the loose ECU conection, just remove the pasengers kick plate, start the car and then wriggle/pull on the plug and individual wires near the ECU. (you dont need to be rough, the bad connection faults under driving vibration so no real force needed). If the car splutters or cuts out you have confirmed the problem, then just repeat until you find the correct wire (you can also pull the plug off and spray the whole lot with electrical cleaner and reconnect after it dries out)
Hope this helps.
PS Coopers Draught LOL