Well, there are rumors that the recording industry is 'salting' the internet with bad files. However, a lot of these are due to faulty 'ripping' (converting existing audio to digital formats, like MP3). Sometimes a glitch in the net traffic corrupts the file. Worse yet, as more and more people download these dinged files, it gets harder and harder to determine if ANY of these are kosher. I listen to everything I download EVENTUALLY, but not always at the moment of download completion. This means others will download that file. If it's bad to start with, then several more bad bad copies of this file exist after they finish downloading; then, more people download from THEM....
All you can do is note the size and full name of a file. When you determine it is bad, find another version of the file with different specs and try, try again.
Happy Liming!
KenJ