Brian, at first I had the same issue you have with my smaller 8400gs card. There is a trick to keep it alive. Install the lastest driver for your card. Afterwards install the new one without removing the older one. Doing that, my 8400GS use the new driver.
Anyone else think its a good idea to install this driver even if your card is not listed? I have the 8600GT as well.
I am not experiencing the lag….but every once in a while(go figure) I get the message OGL has to shut down. I have it back by turning it back on in preferences & restarting PS. I would like to be rid of the nuisance!
To be clear I tried to install the new driver over my existing 178.24 driver but the installer came up with a message saying no compatible card can be found and exited the installation. Indeed nVidia do not list anything below an 8800 card as compatible with this new driver so that lets out my EN8600GT