File downloads have been changed, there's an added layer of security now and it sets up a future feature of allowing multiple files with the same name and/or multiple versions of the same file. All files should now "download" in the browser instead of displaying for certain filetypes (depending on your settings, i.e. mp3s will download now instead of loading in QuickTime if you have it installed).
The biggest change you'll notice is that anyone clicking on a file download link (the ones that look like /h/dl/###) from an external site now have a page pop up rather than just the download. This lets me show a few more ads (and offset the costs of downloads) so I'll be adjusting the bandwidth/credit system soon to account for this.
The update process may have disrupted some downloads between 2am-5am EDT today, but things are settled now.