Yes, the Pro driver has cured the buffer offset problem.
However, there is still the one buffer so you might need to alter it between WDM and ASIO/GSIF progs but you may be able to find a setting that suits all.
Maybe I was out of my head when I did a quick offset test using the monitor mixer as record source, but the recording was actually 32 samples AHEAD of the source track. It is independant of the buffer setting. I suspect the timing is synched to the analog input which explains the monitor mix being a bit early 'cause it hasn't been through AD/DA convertors.
I have my AP running in XP now with these new drivers. It's on a new VIA KT400 mobo with ACPI enabled. Seems fine but it's early days.
One really annoying (but only cosmetic) thing with the new driver is that the old short analog port names have gone . Now it's "M-audio Audiophile Multichannel 1 & 2" and in Sonar, you can't see the important 1&2 bit unless you hover the mouse over the channel dropdown.
