Allen,
See, that's the weird thing: the emailfile and memberslist files were still good - the usernames and email addys are still present (and correct) in those 2 files.
And the profiles themselves were still there, they were just completely empty. Zero, zip, nada...no bytes, no bits.
To rebuild those profiles, I simply FTP'ed a good one to my machine, changed as necessary, saved as their member number profile, and FTP'ed back. Then I went into the CP to verify and fill in any missing info.
The good news is that it's only happened to 3 profiles...fingers crossed...