I had a message from Herr Widmer at HPW-Works.com, the writer of one of the packages I've been looking at, and he has solved the problem b using a thing called a WDM-Wave-wrapper driver: specifically the Waped Wave Wrapper, which would fit in with Keith's idea that internal resampling might be the culprit, but I haven't been able to get it to work myself.

What I have found is one or two measurement packages that actually work completely in the ASIO system and I shall probably settle on one of them. They tend to be at the higher end of the price scale, but I have to get something to use in pursuit of the daily crust, so I guess I'll have to swallow the premium.

One strong candidate is WinAudioMLS from http://www.dr-jordan-design.de/

So if I can't come up with a solution that makes the plethora of WMD based systems work properly I'll probably settle for that.

Ed Form