Tried to reproduce your problem with same Unity version as yours and with SE Live with Walkman ICS, all works fine. Tap and hold, then press home button and it goes to my home screen but the game is still running in the background without crashing.
It might not be a bug in your app, it might have something to do with your particular device and/or your Android version on it. Try running your app on a different device and see if the error still occurs.