Hello guys,
Just got it working. There's a new entry under Upload File in the sidebar, you can now upload up to 10 files simultaneously. Seems to be working fine, at long last!!!
Oh, also, did I mention the size limit has been massively lifted? Although I wouldn't recommend going to the limit, since the method employed by mediawiki is not extremely reliable for large file transfer over HTTP. So If your (big) file repeatedly fails or stalls, let me know so I can up it by FTP.