Using an Nvidia Quadro FX 1000, I don't know if it supports Vertex and/or Pixel Shading - it just happens to be the most recent card available in the lab.
No problem, though - purchase order for a new machine will go through soon, that will solve the graphics card problem if that is the issue.
Its definately not one we have tried. The list of cards we have tried are in our wiki (linked from our main page).
I posted in the newsgroups btw, pointing people to your post.
Sometimes cards claim they support the shade profile we need (which btw has been around for 5 years so we were hoping its everywhere by now ) but they dont actually do, as a result you get wierd rendering results