Try:
1. Tools - Clean project.
2. Uninstall the installed app and then run it again from the IDE.
Well I tried what you suggested but I'm still "locked out" of making any changes. I
did find an earlier copy of this project that I'd saved before finalizing all the field sizes. This one is
not "locked". Good news - now I can fix the sizes to fit my new Samsung! Crazy about the other thing, 'cause I tested changing other projects without any trouble. There
has to be something I did to "lock" it. Not really a bad option to have though. Right?