The errors are not time specific. The TONI_KIDln tasks are failing any time from immediately through to times over about 4000sec.

I did see the odd other task failure too, like this one, but almost all failures were for TONI_KIDln tasks.

Seems to make no different using 6.11.4 and more recent drivers, to the error messages:

<core_client_version>6.11.4</core_client_version>
<![CDATA[
<message>
Nem megfelel� funkci�. (0x1) - exit code 1 (0x1)
</message>
<stderr_txt>
# Using device 0
# There is 1 device supporting CUDA
# Device 0: "GeForce GTX 480"
# Clock rate: 1.40 GHz
# Total amount of global memory: 1610153984 bytes
# Number of multiprocessors: 15
# Number of cores: 120
SWAN: Using synchronization method 0
MDIO ERROR: cannot open file "restart.coor"


<core_client_version>6.10.58</core_client_version>
<![CDATA[
<message>
Nem megfelel� funkci�. (0x1) - exit code 1 (0x1)
</message>
<stderr_txt>
# Using device 0
# There is 1 device supporting CUDA
# Device 0: "GeForce GTX 480"
# Clock rate: 1.40 GHz
# Total amount of global memory: 1610153984 bytes
# Number of multiprocessors: 15
# Number of cores: 120
SWAN: Using synchronization method 0
MDIO ERROR: cannot open file "restart.coor"

There is the odd nan error too, but I would expect to get the odd one of these anyway.

SWAN: Using synchronization method 0
MDIO ERROR: cannot open file "restart.coor"
ERROR: file deven.cpp line 855: # Energies have become nan

Perhaps these tasks are stressing your card and finding a weakness with it, or your system.
I would be inclined to suspend any CPU tasks, close Boinc, restart and just run GPU tasks to see if the failures continue; just in case you are crunching a greedy CPU tasks that hoggs system memory. Per chance did you check how much system memory was being used and are you crunching Lattice CPU tasks?

You might also want to make a RAM testing disk, and boot to it.
http://oca.microsoft.com/en/windiag.asp

You might want to consider swapping the GPU's between systems. That would tell you a lot, but I would be inclined to test the RAM first!

PS. There is no point having 8GB RAM in your other system, running XP x86!

Let a few tasks run when you swap the cards. Drivers should not need updating, so it's not too much of a task. Report back any findings.
Thanks,

Well spotted. There has been one or two of these issues before with the Fermi cards. I think the last one was a Gigabyte as well; perhaps they are cutting it a bit too fine. I’m guessing ASUS got the pick of the bunch to work with. My Asus ENGTX470 has a Voltage of 0.975, and crunches away quite happily at 704MHz. I paid a bit over the odds for it, but now I think it was definitely worth it.

Good Luck,