I am playing DD one week now, and I had the same problem. I run windows XP and Directx V.9. I think that it has something to do with that. The dierectx I mean. I uninstalled the V.9 and I reinstalled V.8 from the game cd and now DD runs perfectly.
By the way I want to thank you all about the help because reading this forum made me solve many system problems and I can now play hours and hours... <img src="/ubbthreads/images/graemlins/wave.gif" alt="" />