Most atrac files are copy-protected by DRM (Digital Rights Management), the only exceptions being those with an .atp file extension. Because of this protection, the files cannot be copied, or converted to a different file format that would then allow the file to be copied.
When confronted with one of these protected files, Switch will attempt to convert about a minute of the file (as part of its protection mechanism) before it gives up. Unfortunately there is no solution to this problem.