Right the CPU was at 50C and the GPU was at 60C. The game ran amazingly, no lag at all and no crashes. It seems to OC you advised me to do has solved the problem as I had not tried playing since doing that. I recommend people with the same issue to also get the updated profiles from ATI.
hope it stays this way as I was sat playing waiting for the inevitable horrid crash which never came. The community is resorting to all sorts to get this game to work properly including deleting audio files and a host of desperate attempts to get some good gameplay in before lag time.