I honestly thought that the current HD problems would be fixed in a driver update, but considering that has not happned for quite a while its time to take matters into my own hands.
So, ordered a HD card and will start working on a fix the next week. Hopefully a patch will be available soon. When that is depends on the nature of the problem.
Just wanted to let you all know.
EDIT: Installed card today, fixed one bug and found fix for another. Now I am working on making the last fix fit with rest of engine.
Have been reported by me and several users shortly after release of Overture. I think I have waited long enough
Hopefully it is a simple fix. Worst case scenario is that OpenGL-Cg (the shading language) is not fully compitable, which would mean a major rewriting of shaders.