No audio data found error on iPad 2

The app worked fine on my iPad with iOS 5.0.1. Today when I attempt to play some mp3 audio files, the app displays "audio error - No Audio Data Found" message. Sometimes it plays and sometimes won't play. Then I try holding down the on/off switch and the Home button until you see the Apple logo, but not working. I note that my Verizon 3g iPhone also has the same issue. Hope someone else are able