No.  Originally, the piano track was a midi track using a hardware instrument.  However, I am taking my Mac to the Mac Store, as I updated to osx 10.8.3, and I have maaaaaaaany other problems beside this one, hopefully they will simply do a clean install and I'll be in business.  Though, I am curious though as to your question, any information would be greatly appreciated.  Sometimes it does feel like "us against them" in the technology war.  Thank for your response.

I was just trying to isolate the problem--to be sure that it was caused by the piano in the track as opposed to something wrong with the track settings.

1. Have you tried temporarily muting or deleting the other tracks, one by one, to determine if the piano will come into line as you free more polyphony?

2. If you just record a solo piano track with the metronome on, does it play back correctly?

3. Have you tried moving the piano to another track--swapping the piano part with another part?

4. What host are you using--Cubase, Logic,...? Someone else here might use it and know of specific things to check.