I can no longer play sample m3u audio tracks from Amazon.com, although all is OK with other streaming audio mp3 and m3u. I'm using Windows Media Player 11 and it is the default player for m3u files. Recently I installed and then uninstalled Apple itunes and quicktime, but I can't be sure if the timing was concurrent with the problem.
I also attempted to run regsvr32.exe wmp.dll from the command prompt as suggested in an EE post, but got error message 0x8002801c. Later I came across a warning that running this could mess up other things.