Thanks for the responses, guys. As far as optimization goes, I found this link over at focusrite's site. Followed their advice and it did noticeably improve my PC's performance. I had several of their recommended settings set correctly, but there were a few that I'd missed or didn't even know about that really helped. The recommended settings cover Mac and the various recent flavors of Windows. Here's the link:

https://support.focusrite.com/hc/en-gb/categories/200693685-Optimisation

I even posted a message here about this site, but got no responses. Here's the message I posted:
https://www.pgmusic.com/forums/ubbthreads.php?ubb=showflat&Main=74384&Number=515636#Post515636

Noel, to answer your questions, yes I was having problems with both the 64 bit and 32 bit versions. And the MIDI track was just plain MIDI so no vsti/dxi.

The problem has been occurring with various tunes, not just the current one. That was the reason why I felt compelled to post my woes.

Now, about the RT tempos matching those of the song, to be honest this isn't anything I've given any thought to. I will frequently play around with the tempo of styles that I'm trying out, or even after I've selected one. So this might be a possible reason for some of the problems.

But when you asked if this is happening to other songs, to be honest I was listening to only one song. But get this: this song was one that was born this morning. I gave a set of directions to the Melodist and then told it to generate a song for me. So everything about that song, and I mean everything -- except for the volume and balance and such, which I adjusted -- was composed by the Melodist. So you'd think BiaB would be able to handle it, wouldn't you. But it was one big distorted mess.

But anyway, I did as you requested. Booted the 64 bit version this time and then went and listened to a bunch of tunes I wrote -- about a dozen or so. And they all played back perfectly. Not a single Rice Crispy anywhere. So then I called up the song that got created this morning and gave it another run through. Prefect. No Rice Crispies to be found.

Dammit. I don't like it when software makes me a liar -- or a fool. I don't know why it decides to behave like this. The fact that it does sometimes and doesn't others means it is unreliable. I can't depend on it. And what's worse, I'm not sure how to cure the problem. Maybe just a simple reboot? I dunno.

Best,
Michael

My Music:
https://soundcloud.com/michaelmcbroom/albums