Sullivan, James (NIH/CIT) [C] wrote:
This is a known problem but I'm not sure where Mediawiki.org is on fixing it or whether they are attempting to fix it, though I have heard rumors of a fix in 1.17. The problem stems from Microsoft (surprise!) having changed its format for Office 7 documents. Its format gives its files a mime-type of a zip file, so when Mediawiki checks the file it sees a docx extension but when it looks at the mime-type of the file (a binary string near the beginning of the file) it sees what appears to be a zip file. Thus the "corruption". These checks help prevent users from uploading malicious files with innocent looking extensions, like uploading a nasty zip file with a jpg extension for example.
Well, like OpenOffice.org's Open Document Format (http://en.wikipedia.org/wiki/OpenDocument) Microsoft DOCX files ARE zip files, only with the "wrong" file extension. You can check this by changing the extension to ".zip" and opening it with your favorite zip program. In fact, it's an XML based file format like ODF.
A workaround for the problem at hand might be to make docx files "real" zip files by zipping them before uploading. You can coax MediaWiki to upload any file type this way.
hth Frank