Bum! Thought that patch would work
DAB, the card is overclocked out the box by default (why it's called 6200 OC) but only by 25Mhz on the core, 375Mhz instead of 350Mhz.
The card needs to be run at 350Mhz and tested on the game again, if it still does the same it eliminates the overclock as the problem and then we clutch at straws!!