Okay, thanks for the latest responses. I'll address your questions and points in the order they were posted.

Mike, whenever I'm experiencing issues like this, whether it is in BiaB or something else -- like Cakewalk, for example -- one of the first things I do, besides idling every other piece of software I have running, is I boot Windows Task Manager, and check to see what Processes are running. The amount of RAM they're consuming is what I pay most attention to, but even minor players that don't need to be there get the boot. So I'm confident that, when this was occurring, there were no resource-sucking processes going on.

You wrote, "As a matter of interest have you made an exception for Biab for your AV programme that can be quite a big footprint checking everything you do."

I don't know what this means. AV Programme? Is this a Win10 thing? I'm still running Win7, as I pointed out above.

About my machine's minimum processor state, I found out about that a couple months back when I was discussing similar problems with one of the PG tech staff. She stepped me through how to check, then adjust it to 100%. So I did this, but when I read that a M$ update may drop it back down to 5% again, I checked it again just now, and sure enough, it was back down to 5%. Dammit, MicroSloth, when I set something I wish you'd leave things the hell alone! That could have been most of my problem right there. But it doesn't explain why things cleared up the way they did yesterday.

Mario, I have my card's buffers set to 512 at the moment. When I began to run into this problem, I checked and they were set to 256, so I bumped them up to 512, and it didn't affect things then.

My "interface" is my trusty old M Audio Delta 66 card, capable of 24/96k recording -- although these days it seems like I'm always just using it at 16/44.1k. My Delta 66 has a dedicated I/O device, called OMNI I/O, which provides most options a full-featured USB interface would, except MIDI unfortunately. Here's a link to a page at ZZSounds which gives a good description of the OMNI I/O:

https://www.zzounds.com/item--MDOOMNIIO

RobH, I was using Coyote for a single MIDI track. I don't see how a single MIDI track would affect performance one way or the other. The other 5 tracks were RealTracks.

Bob, it's good to read your Win10 PC is running things fine. The thing that concerns me the most about upgrading to Win10 is my Win7 drivers -- especially the driver for my Delta 66. M Audio hasn't written an update to that driver in years. The current driver was written in 2012. I checked at the M-Audio forum on this issue though, found a thread where an M-Audio 1010 (same driver as for the Delta 66) owner was worried about Win10 compatibility and it was verified in that thread that the Win7 driver works with Win10. That's a bit of good news.

Best,
Michael

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