There's a Settings dialog box, wherein lies a checkbox that turns WDM off when you're not running audio. In parentheses next to it, it says (Keep checked when using M-Audio Delta) or something similar.
Preferences>Audio Devices>... in there. Snoop around, you're bound to find it! It's not in front of me, I have no mind for remembering 'minutae' (imagine my learning curve!). I don't know if this fixes the problem, but on the n-Track forum there are cats who are hip to this. Dude. Dig it.
I was Using MME with my US-428, and it was allright for me. However, just for kicks, I switched ASIO back on (big selling point for the US-428), and I've gotten it to work. I am, unfortunately, now experiencing another problem! I don't think it's driver-related...But Flavio seems to be pretty good about fixing things, so I remain hopeful.
I paid $75.00 for the 24-bit, and if I can tune this baby up nice and tidy, and learn the rest of what I need to know for MIDI, etc., I'll be happy.