He is throwing several invalid results with that rig but I'm sure that he'll get that sorted out, he did abort a few GPU AP's very recently so maybe they were the cause.
I updated a few rigs to 41zc Cuda50. The computation on GPU is faster. I also added a new host to the farm. I could not get Boinc 7.0.28 to work at all on Windows 7 Ultimate 64bit, so I used version 7.0.44 instead.