Thanks, scook. Not sure how to do what you suggest. How does one APPLY and RENDER to the clips (not complete tracks) that did the region disappearing act? Are you suggesting there's a method for reinstating my region work or are you saying I need to start from scratch?
UPDATE: I've decided I don't like pressing CTL-T to get regions as it seems that with multiple regions, when I enter the editor, they're all combined into one editor as opposed to doing manual Melodyne work where one edit session applies to only the clip to which I applied Melodyne.
UPDATE2: After clicking BYPASS REGIONS multiple times, I got back my region. But now the RENDER REGION is greyed out??? And sometimes when I select BYPASS, I still get no sound from the region. Crazy !