Hi Nige,
Thanks for your feedback, I think it has moved on quite a bit since the version you tried, haven't posted the latest version, but have been passing them to someone I think you know and he appreciates the improvements, have been optimising memcpy which has made a big difference, can't believe I am comparing the sonic differences between assembly instructions. There is a wasapi_test program in the testing folder on the rapidshare site which you can download to see which are valid formats for your device, MQn plays 24 bit hirez in 32 bit packed containers so that may be the issue.
Core doesn't have WASAPI capability, until that is cracked it won't be possible.
am using ws2012 gui