Thank's Fox, I tried all that and no luck it's still exactly the same.  Last night drove me mad with all the flashing.  It gets worse if there is cloud around.  I had the latest drivers, but dropped back to the ones you suggested, just in case.  I run a lot of things on this machine and I must admit AH is the only one that seems to be giving me graphics problems.  This hardware cost me a fortune so I am not about to do an "all change" again just because of the problems here.  I will be back after the next upgrade :-(
Zeb