cogadh: Thread is TL;DR the whole thing, but I though I should mention (in case it hasn't already), the Steam store page for Risen now lists TAGES as third party DRM. I don't think it listed it when I checked it about 20 minutes ago, so they may have just added it.
EDIT - I just noticed another example of the stunning lack of quality control when it comes to Steam and the game descriptions. In the game's minimum requirements, it lists "256 MB
DirectX™ 9.1c compatible graphics card (nVidia® GeForce® 7900/ATI Radeon™ X1800 or better)", "
DirectX™ 9.1c compatible graphic card driver" and "100%
DirectX™ 9.1c compatible sound card"... there is actually no such thing as "DirectX 9.1c", so I guess none of us have compatible hardware.