Thomas Dalton wrote :
That just tells it not to check if the file's contents matches its extension. It seems MediaWiki doesn't know how to recognise .doc files, I'm not sure how to fix that.
Since I can upload doc files on my wiki without any problem, it seems more probable to me that she has a problem with incorrect mime type (silently corrupted files) or some server-related configuration, but I don't think it's a mediawiki-related problem.
Don't know how to fix that either, using $wgVerifyMimeType = false; is very insecure according to mediawiki.org : (see http://www.mediawiki.org/wiki/Manual:Mime_type_detection)