Sonar x1 & windows recording problem

Hi there,
I'm an experienced Sonar user but at the end of my wit, experiencing a recording problem with sonar x1 with windows 10. I recently had to get a new laptop and with it windows 10. Of course I knew that would mean problems, but I've never experienced this one when upgrading. Windows & sonar are saying that the audio interface is using the right driver, but always when I start sonar x1 I get notified that the interface only supports 16 bit (which is not true, of course). OK, I can change the bitrate it each time & that's just slightly annoying. The real problem is that I can't record or rather:  though sonar appears to record normally (you see the audio wave) is squeezes the record into little lump that sounds like the recording played 10 or more faster. So the recording is in no sync whatsoever with the recording, and unrecognaisable as music anyway due to the speed in which it's played back. I've tried all possible settings but can't figure out anything that helps. After a while thought it must be a problem windows 10 is having with my m-audio fast track interface, since it's 5 or so years old. But I'm experiencing exactly the same problem with M-track 2x2 which is new enough so windows 10 should be OK with it. Is anyone using sonar x1 successfully with windows 10? Anyone any clue how to solve this problem? (I thought I had experienced them all over the years, but no.) Thank you!