Just ran two passes using the Microsoft memory checker that comes in Windows 8. Both passes passed. Took around nine hours to complete.
Going to attempt the long recording using the internal soundcard, instead of the M-Audio FastTrack USB interface. Then, I’ll try recording with a different computer altogether, and see if the choppiness disappears in any of these cases. This may at least, help rule in or rule out Audacity as a cause.
I was hoping to record a 36-hour Christmas show that starts on Christmas Eve. But perhaps I’ll have to be here, to stop it periodically, or just use a really long latency setting, and pray that the noise stays away for 36 hours.