I was having problems at GPUGrid running one of their applications. It turned out that the problem stemmed from an NVidia driver (19745) and what was read by Boinc, and only effect Windows Vista and Windows 7 (both are 64bit versions), not Win XP x86.

On Vista and Win 7, the 197.xx drivers are reporting incorrect RAM amounts to Boinc, reporting slightly less values. We think this is causing the tasks to immediately fail (thinking there is not enough RAM).

I tried the 19745 drivers on several versions of Boinc from 6.10.18 to 6.10.56, but all were still reporting the incorrect RAM amounts (475MB instead of 512MB).

After uninstalling the drivers and installing 196.21, I managed to start running the previously failing tasks, and Boinc reports the correct RAM amounts.

Tested on Vista with four GT240's and on Win7 with a GTX260sp216.

Again, the problem does not occur on XP x86 with the latest drivers.

Perhaps a note on the driver download page to match known working drivers to Boinc applications and operating systems would help others?

Boinc suggestions:
Would still like a seperate Tab on Boinc for GPU config.
Would like to be able to set cache levels for GPU and CPU seperately.

Also think that you might want to use different versions of Boinc for different operating systems (given that the drivers are so different, eg between XP and Vista). Might simplify things (development and troubleshooting), and rollbacks would effect less people!

I've asked Nvidia on their Cuda GPU Computing Forum about what's changed with 197.xx drivers, but had no reply.

Cuda-Z and Boinc report less Memory with 197.xx drivers

Claggy

Actually 196.21 still fails under Win7 with the GTX260sp216, using Boinc 6.10.51. I'll try Boinc 6.10.56!
That was very messy.