Hey all, I just installed my GTX 580's that I stepped up to form GTX 480 SLI. No problems with the install using the new 266.58 drivers. Issue I am having is with stability testing programs, in particular EVGA Scanner OC and FurMark (Multi-GPU). When I start the test both GPUs will go to 99-100% usage for a few seconds then one of the GPUs will go down to around 50% usage while the other stays at 99-100%. It does not seem to be any one GPU either, one test run, GPU0 will stay at 100% the next time GPU1 will stay at 100% and the other will settle at around 50%. To make sure it was not my cards or setup I tested some games and they work perfectly. I use Metro2033 for example, as it seems to use the most GPU power, both cards will stay around 95 - 99% usage constantly. Other games work the same with both GPU's usgae being identical. This problem only seems to be with stibility testing programs. Before I sent my GTX480s in for Step-up i was using the older 263.09 drivers and never had this problem. Has anyone else encountered this problem with GTX 580 SLI ? I highly suspect this to be a driver bug.