I may need to look into this But I don't think direct input pads should work by default.
Is it possible the pads have been setup to work with another opengl game and DP2 is using the same config?
I'll look into this and try some of my own pads.
BTW it's great you got it running on a crt. I's something I've wanted to try but not managed to do. Please send a picture if you can.