Up until Friday, the MPEG-4 Ringtone download links did not work as expected with Internet Explorer. Instead of saving the files with an “.m4r” file extension required to import ringtones into iTunes, Internet Explorer would save them with the generic “.m4a” extension.
This is a known issue with the way the Amazon cloud file storage solution, Amazon S3, sends files and how Internet Explorer interprets the files. I have gone and fixed all of the existing MPEG-4 ringtone files so that they download with the correct file extension. I have also altered the method that I upload the files to Amazon S3 so that new MPEG-4 ringtones will be marked with the appropriate flags for download.
I apologize for the inconvenience and not catching and fixing this issue earlier.