title: Amazon S3 Downloading .mp3 and .wav files as .zip
body: <p>I send out music files (.mp3 and .wav) and give the recipient the option to download individual files as .mp3 or .wav, or a bundle as .zip.   I upload all these to my s3 account, and force download with PHP.  All has been fine until about two weeks ago, when the individual .wav and .mp3 files that I never zipped up were being downloaded as .zips.     </p>
  
  <p>Users click the option to download the individual tracks as .mp3 and .wav and every time a .zip file downloads, which obviously doesn't extract as it's not a valid zip.  Renaming the zip to a .wav or .mp3 (depending on what was downloaded) works fine.</p>
  
  <p>For nearly five years this has worked fine until two weeks ago.</p>
  
  <p>Any possible help please as I am lost?</p>