My work computer has a problem, which is that I can no longer download/view mp3 or pdf files. Attempting to do so leads browsers to either stall out, or download a partial and broken file.
The problem happens in all browsers, and I'm quite sure that it's MIME types, since I can change the extension of a file to download, and it still won't download correctly. Zipping up the same file allows the download to function.
It's not a problem of particular websites, as I can't seem to download a pdf or mp3 file from any website anywhere.
It is worth noting that I am behind a proxy, but that no one else on the proxy seems to have these issues.