Some thoughts:

Make sure to have a delayed startup when running gpu tasks. Without this delay problems can arise

Since these tasks are so short, there probably won't be any checkpoints that will take place in the event a restart/shutdown occurs.

When downloading the ATI driver you have to make sure the OpenCl driver is downloaded as well. I believe that this is usually found in the developer package for ATI cards. SDK?

Playing games and watching movies should be avoided when running gpu tasks, since gpus are much more susceptible to errors when they are also being used for other purposes.

So far I'm at 4 pages of valids and counting.

Looking better knreed

I have had a few run for over 5 minutes with 0% progress, until I hit snooze GPU and they started running normally!

Win7 with 5870s CF.

My nVidia 430 finished another one. This time I freed up a CPU core and the WU took 18 minutes 49 seconds "cpu" time and 18 minutes 59 seconds "elapsed" time. Win 7 Premium x64 BOINC 6.10.60. So far no troubles found. I will note that when no CPU core was free, the previous WU reported .30 CPU hours under the WU status page and with a CPU core free for this last one took .31. I will try and monitor this to see if it changes any/much. The CPU is a Q8200 2.33 GHz stock settings.

Edit: 3rd WU was 16 minutes 15 seconds CPU time and 16 minutes 21 secons elapsed time. WU status says .27 hours this time with a freed up core.

Edit2: 4th WU was 19 minutes 5 seconds CPU time and 19 minutes 18 seconds elapsed time. WU stats says .32 hours with a freed up core. And when I say freed up core, I am manually telling BOINC Manager to use 75% of the four cores. The work unit however frees up its own core within that 75%, so I drop down to crunching 2 CPU work units when the BETA needs the third. I'm noting this so that others will know that the setting is indeed working.

Edit3: 5th WU was 19 minutes 23 seconds CPU time and 19 minutes 59 seconds elapsed time. This time I told BOINC manager to use 100% of the cores. WU status says .32 hours.

I received only one WU. It immediately stopped with the error:
<core_client_version>7.0.28</core_client_version>
<![CDATA[
<message>
- exit code 293 (0x125)
</message>
<stderr_txt>
Commandline: projects/www.worldcommunitygrid.org/wcg_beta3_img_6.47_windows_intelx86__cuda_hcc1 X0000038270789200409250016.jp2
INFO: gpu_type not found in init_data.xml.
INFO: GPU device not specified in init_data.xml. Checking Commandline.
ERROR: GPU device not specified in init_data.xml or on command line. Exiting.
17:32:58 (6776): called boinc_finish

Can I see or change "init_data.xml?

My problem now is as WCG GPU Beta's have finished and reported. I can not run GPUGrid unless I suspend WCG..I think somehow the CPU WU's that were d/l with Beta are linked to my GPU still.

Edit: Seemed to be with the 3 ver. 611 WU's I had. Working for now.