its probably related to the DELAYED RECORDING MODE FEATURE....hitting the Start Recording button, when the source has not yet started, and then SOUND TAP ACTUALLY starts to record when it hears sound.....
THE APP SHOULD BE RECONFIGURED TO RECORD THE SILENCE AS SOON AS THE RECORD BUTTON IS PRESSED, AND THEN FADE INTO RECORDING'S FULL LEVEL WHEN THE SOUND STARTS ( TO AVOID A SUDDEN STARTUP OVER PEAK DISTORTION). IF THE INITIAL START UP CAN BE MADE PEAK DISTORTION FREE, THIS FEATURE CAN BE MADE SELECTIBLE.
BUT NO WAY THIS APP SHOULD SHUT ITSELF OFF WHEN THERE IS A SILENCE BETWEEN SONGS!