I bought Poweramp for my Android device and am having trouble gettings songs onto it from my PC. I know there are some WMA files that Poweramp can not handle; however, I am having trouble with m4a songs. Some of these were initially in the WMA format but I erased thhose and re-ripped into m4a. I used to receive an error message someting like not all file formats are support. Now all I receive is transferred failed in a separate Winamp window. Is Winamp the right PC program? Should I be using another? What am I doing wrong?