It seems as though you might have named the files “000.MP3.MP3” rather than “000.MP3”.

If the sample MP3 files that are in the folders we ship with the product do not show the ",MP3" file extension (for example they show as "000" instead of "000.MP3") then you need to change a Windows setting.

This can happen if you have the Windows setting "Hide extensions for known file types" turned on.  

Showing Extentions on Windows XP:

To change this on Windows XP you go to the Tools menu in any file window, go to Folder Options.  Then click on the View tab.  Then remove the checkmark from "Hide extensions for known file types".

Showing Extentions on Windows 7:

Click the "Organize" button in the upper-left in the folder window that contains the files, then select "Folder and Search options", click the "View" tab, look for the "Advanced settings:" section.  In there you will see a section for "Files and Folders"... remove the checkmark from "Hide extensions for known file types".

After turning that setting off and looking at the files again doesn't answer your question then you can e-mail us your MP3 file and we can take a look at it to rule it out as the issue.