It says my track is 'too hot' or is stuck on 'Preparing for transcoding...'? Is there something wrong with the file?

There's nothing wrong with your file. When the system can't process a track, it comes back as "too hot". When this happens, we recommend that the track be deleted and re-uploaded. When uploading again, please wait until the orange bar has started to process before clicking 'Save'; and leave everything except the title blank on the upload page.

If that doesn't seem to help, please try the old-skool uploader or Scup.