I took your advice on Wed last week and contacted Kufatec. I submitted a web enquiry on their site and they replied in under 10 mins! They asked for 3 dates/times in the near future I would be available (I was off work last week so said 3 days in a row chancing my luck!) They replied again in under 10 mins and suggested straight away if I could!!!
I connected the dongle to my laptop and then connected to the teamviewer session they setup. They then proceeded to reapply the file for the update and then asked me to connect to car. (luckily my wifi reaches to the drive).
After about 20 minutes and several attempts and what looked like a few versions of the file being copied onto the dongle the process went through and on this occasion I notice an additional "ping" and was asked to turn ignition off/on etc and he announced it should be ok to test drive.
I disconnected and notice within 30 yards a traffic sign pop up on VC! Excellent service although a bit nervous of not knowing the person controlling my laptop.
I asked what they thought the problem was and it was a bit vague but something along the lines of they had to make space in the coding to allow the settings to fully be accepted... perhaps in the memory space for the settings in ECU I don't know, but all working!
One thing I notice and thought about is that if someone buys a dongle in the future, it might be worth connecting laptop/PC to the dongle prior to going anyway near the car and taking a copy of the one file that's on the dongle . Then if you apply the file/dongle to your car you might be able to copy the locked file off should you need to reapplied the locked file back on your car and put the "clean" one on the dongle and use on another car....maybe