Thread:Project:Support desk/Can't Move File Pages for xls Extensions

I can upload excel files fine, but they can't be moved (sometimes). I get an error "The new file extension does not match its type". I bumped into a similar problem a few years ago that was resolved by added some lines to mime.info and mime.types, but it seems to have resurfaced, now for excel files. Perhaps during my last upgrade (I'm on MW 1.21.2, PHP 5.3.10, MySQL 5.5.32). Mucking about with $wgVerifyMimeType, $wgStrictFileExtensions, $wgCheckFileExtensions, and $wgLoadFileinfoExtension seem to only have an effect on whether the file can be uploaded or not.

While it might just be a coincidence, the img_media_type field in the images table is set to 'UNKNOWN' for the files that can't be moved. It's as though some xls files are typed correctly (Manual:MIME type detection) and others aren't, which blows up when trying to move them.
 * 1) What might I do to correct this problem going forward?
 * 2) Is there anyway I can fix/rebuild the images table based on the files already there? re-type them or something? There's 2000+ files, and it'd be nice to not have to go through them by hand!

Thanks!