Topic: Finally!!Multiclient ASIO + WDM grief solved!!
After so much time wondering why I couldn't get multiple apps to use different outs on my HDSP setup at the same time, I finally figured it out:
If you use "interleaved" setting in the DSP parameters and you set your WDM parameters for 5.1 surround, you're telling the system to use 6 consecutive channels of audio on your card. If your ASIO host is using any one of them, none of the others can be used by the WDM system. There is some give in the drivers if an app is already using WDM and you subsequently instantiate your ASIO host, but that can lead to some unstable behaviors (single channels of a pair not working, for example).
It seems simple and logical in retrospect, but it's been frustrating me for a long time. I sincerely hope this helps someone else :-)
MBP = HDSPe Expresscard: MF1