Ive never heard that and the last Sapphire we flashed is still working great, at well over stock 6970 clocks. I think it could be card dependent. Probably vendor dependent. Since Sapphire, Diamond and Ati/AMD are all so close in the computer world it would make sense that their cards are more apt to flash up? Companies like gigabyte, asus, and xfx that all double dip probably don't have the same stability in their "reference" model. Same thing as Evga and Nvidia.