I think I _may_ have solved the problem. (At the very least, the real tracks backing with the original melody currently sounds fine.) Here's what I did:

I read the FastTrack Ultra Manual several times. Not the best user manual, I must say. From that, I reset the driver configuration to:

bypass on channels 1/2 and 3/4 (this removes all send to the internal FastTrack DSP)
ASIO buffer size set to 256
enable asio direct monitoring

all other parameters were left as originally indicated in my previous posts

I am at a loss to explain why these changes now have corrected the problem. So, I only tentatively offer this as a solution. I'll shutdown and restart my computer, and I'll post back what happens. Wish me luck.

BTW, Noel: thanks. Yes, I agree with you, resetting to factory defaults in 2011 is much better than in years gone by, much better.

Bob aka jazzwombat

Soundclick: www.soundclick.com/BobBelas