Not sure if it is of interest, if not, pleaseignore this post:

I perhaps have found the reason for the message above.
The terrain demo posted somewhere here in showcase also shows this error message. I took a look into the files (it is not resourced) and saw it's using a terrain with shader applied. Not sure if the shader is a problem, as everything ello released is running, but it might have to do with the terran.

The campground demo presented a while ago, features terrain without shader and ran without any problem.

Too bad that I can't see the nexus/video memory values of the demos, it might help to get an idea what is wrong with my (and some other) system(s). Maybe it indeed is a driver issue, I don't know, but I doubt that the demos mentioned are using more than 64MB video memory..