it is recording at this high speed.
No. It's recording slow. It's producing a song that
appears to be playing fast. If you record a 60 second show, but the computer isn't fast enough to capture all 60 of those seconds, then you might get a 58 second recording. The resulting show will play two seconds faster than what you were expecting. This process is happening down at the sample level, so it doesn't actually give you a one-second hole or noticeable distortion, but that's the idea. It's like a thin line of sand on the kitchen table and someone goes through and removes one grain here and there. It looks like the same line, but it's shorter.
I have loads of free disk space, and it's recently been defragged.
Exactly correct. It doesn't leave a lot of options when you do everything perfectly properly and it still doesn't work.
I'm one of the Mac elves trying to diagnose a Windows problem, so we may wait for someone competent to dig further [backing slowly away from the computer].
Koz