I had a crash problem, and I'll share the fix here, because I didn't come across this one yet:
The Divine Divinity demo has a configuration tool (a symbol of 3 squares) that lets you choose the rendering method. It is by default set on Direct 3D, but you can change that, as I did.
I never had any problem with the demo, it ran fine, but my full version crashed constantly. Until I remembered the demo had given me the option to steer away from Direct 3D, and the full version hadn't.
When I realized that, I put the configuration tool from the demo into the full game registry and started it up there. Now I could select something different than Direct 3D, and I didn't have a problem anymore.
It would have helped me greatly if this fix had been mentioned in the technical support page that I found. Following the tips there - like updating drivers - gave me more new problems instead of solving the one I had. Although it's also a bit that the full game configuration tool didn't have options that the one in the demo had???