Right on fatbobuk!!
I am still waiting for the new Kingston RAM to arrive (from a different supplier as the original does not stock Kingston). The system with the Corsair RAM still has the cold boot memory failures. Bizarrely enough for the first time ever it cold booted fine this morning - which shocked me. Could it have miracolously fixed itself??? NO! I switched it off, had breakfast and tried it again and the old familiar combo of blue Memtest screen with bright red flashed back into life again... This is interesting - it would explain how it passed the supplier's testing - it can very rarely start up correctly. If this was purely a thermal issue on the RAM I would not expect to see this variance.
The saga continues... will let you know how the new memory works.
If that does not resolve it - will RMA the motherboard, Corsair RAM and processor back to supplier.