And interestingly, now that I try to do some batch processing with Bridge, bridge appears to have the same file recognition issue. I guess this some sort of OS permission issue, not Lightroom. Seems like something is corrupt with the majority of these files where certain apps simply don't recognize them.
If the files don't have a .TIF filename extension then add an extension to one of the files and then see if it will import.
>If the files don't have a .TIF filename extension then add an extension to one of the files and then see if it will import.
Bob is right. That is probably the issue. Lightroom doesn't recognize the old filetype/creator metadata codes that Macs used to use 20 years ago so won't recognize that they are image files if there is no extension. You might not realize there is no extension as Mac OS X stupidly hides those by default. You should always turn that option off in the Finder presences->advanced.