WIndows 7 64-bit, got the DIrectX error on startup.
Ran the patcher as linked in this thread, everything AOK now.
Though, I do have to point out that I set my PC to download and install every available update, and it would appear that DX9 is not a part of that. If this is something that all Win7 users need to run, then perhaps it should be noted. (Ever better, make it run without having to do this?)