Are you sure you are downloading mp3s and not wma files. (look at the extension, rathere than the icon). Either way The downloads you are getting sound like spam files. These are usually very small.. 134.5 kb is a famous size. Make sure you download a file of around 3-4MB. This is the normal size for an mp3. If any download instructs you to go to a website, delete it and if you can mark it as junk.
I hope this helps
