yeah your errors are most likely because of the overclocks because the error happens after a few minutes of the WU. if you get an error in under 15 seconds, the it's most likely because of the WU, but this doesn't seem like the case. lol it's a bad idea to clock your cards to try and match my numbers. my 295 is most likely a better clocker than the average 295. i'm running it at 1585mhz shaders with this co-op version, and XP also gives a good boost to the GPU utilization. if you switch to XP, you WU completion time will closer to mine. i have a regualr dual pcb 295 coming in soon, so i'll try to max out the clocks to see how it compares to the co-op version. maybe that one will be a better comparison to yours. what's your max stable OC?

btw, what's the difference between the gtx285 vs gtx275 in terms of crunching? both have same shader cores, with the 285 having barely faster shader clocks. any kind of shader overclocking will cancel out this advantage, and memory bandwidth and capacity does not matter, so is it safe to say a 275 = 285 when crunching?