I'm running SLI 8800GTX(M) with unofficial drivers (from laptopvideo2go DOX185.68), and have spent the weekend troubleshooting CMSF and this error.
I installed the MS hotfix mentioned in an old thread here, but i'm not convinced that it did alot. What seemed to help was selecting single GPU mode in the nvidia control panel, and setting AA to SLI mode ie only one card used for display but both for calculations.
Running in SLI performance mode, i would have horrible problems where the screen would switch to black and then back to the game, everytime i selected or deselected a unit. I could usually provoke the Opengl 14 error by switching units very fast.
If you are not running in SLI mode, then i can only suggest the MS hotfix.
link: http://support.microsoft.com/kb/953186
Does anyone know what the official support is for SLI mode and CMSF?
because as i mentioned, for me it seems partially broken.
I should just add that the problems mentioned happened with both the official drivers for me (179.48 as its mobile version) as well as all the unofficial newer ones.
Running on vista.
Cheers