EUREKA! I HAVE SOLVED THE PROBLEM.. For anyone inerested about those files that would randomly download as a plain "non mp3" document which wouldn't launch.. The problem was- All of those documents had one thing in common when compared to the others that downloaded as mp3s... The file names were too long... That's it. I just had to go in and rename the file (shorten it up) and add .mp3 to the end. The mp3 icon would appear as soon as I renamed it and clicked off of the title bar.. That simple. Shorten the name and add .mp3 to the end.

Thanks for everybody's interest.