Maybe I should have been more detailed in my descriptions
I did calibrate the machine again as per the instructions (which are not very user friendly - they are English translated from some ching-chong language, and assumes you are not a complete beginner!)
The instructions state to put a wheel (any wheel) on the machine and calibrate it with a 100g weight. I followed the instructions and used an old (crash damaged) Porsche wheel I have in the garage.
For each of the wheels that I balanced, I did input the measurements as required before spinning it to balance.
The machine looks to be the same as this one that is available to you in America -
UnitedProducts Wheel Balancers Model WB-1100 Just mine is blue and not red
As the only instructions I have are what was supplied with the machine and what I have found on YouTube, I have no idea if I am missing some details.
Based on the fact that the machine does eventually indicate that I have managed to balance the wheel - even if it might take 3 or more spins, makes me think that maybe it is me not putting the stick-on weights in the correct location and as such the wheel gets put out of balance again - if this makes sense?
I will just have to put the wheels on the car and give them a go - all it will cost me is my time and the price for more stick-on weights! And I will be pleased once I manage to get it all sorted out