Yes, I'm experiencing the same issues (using D3D11 codepath however) with my HD6950 (2gb). Vertices will be randomly displaced from frame to frame as if memory was getting corrupted somehow.
Ventuz can you check if running a GPU-intensive application (like furmark) in the background while running your software removes the artifacts? Because it does for me which suggests a driver bug. (of course I'm not suggesting this as a solution, it's just to see if our issues are related).
PS: still not fixed as of 11.10.
This issue seems related to GPU temperature. For instance:
GPU at 30-40C -> monstruous artifacts everywhere with crazy vertex stuttering/displacement seemingly at random on meshes
GPU at 40-50C -> a lot less artifacts but a few remain
GPU 50C+ -> virtually no artifacts left.
We did not encounter this problem since the Hotfix 11.5b:
At least non of our customers reported any further problems.