http://bugs.winehq.org/show_bug.cgi?id=3290
------- Additional Comments From oliver_stieber@yahoo.co.uk 2005-26-09 18:33 ------- The d3dx9.h comes with DirectX SDK, it's not in Wine yet because wine doesn't have a d3dx9 implementation in it.
Vertex shaders shouldn't cause a crash without an error being raised whatever graphics card you have especially when you consider NVidias drivers are much better than ATI's.
Can you try to run the demo under wine please, and I'll try and get someone with a Nvidia card to try out Dungeon Siege 2.