scanner.enable() throws ScannerException

My app sometimes (yes, sometimes) get the following exception when trying to init the Motorola TC55 scanner:

 

10-23 20:18:54.237    1895-1895/com.amazon.yms.mobile.tasks W/System.err﹕ Throwable occurred: com.symbol.emdk.barcode.ScannerException: Failure 10-23 20:18:54.237    1895-1895/com.amazon.yms.mobile.tasks W/System.err﹕ at com.symbol.emdk.barcode.Scanner.enable(Scanner.java:352) 10-23 20:18:54.237    1895-1895/com.amazon.yms.mobile.tasks W/System.err﹕ at com.amazon.yms.mobile.tasks.EMDKScannerWrapper.initMotorolaScanner(EMDKScannerWrapper.java:143) 10-23 20:18:54.237    1895-1895/com.amazon.yms.mobile.tasks W/System.err﹕ at com.amazon.yms.mobile.tasks.EMDKScannerWrapper.onOpened(EMDKScannerWrapper.java:261) 10-23 20:18:54.237    1895-1895/com.amazon.yms.mobile.tasks W/System.err﹕ at com.symbol.emdk.EMDKServiceConnection.notifyonConnected(EMDKServiceConnection.java:112) 10-23 20:18:54.237    1895-1895/com.amazon.yms.mobile.tasks W/System.err﹕ at com.symbol.emdk.EMDKServiceConnection.onServiceConnected(EMDKServiceConnection.java:92)

 

 

I perform all the initialization work suggested by the tutorial in the onResume() method, and de-init the scanner and release the resources in onPause() method. Once the work at current activity is finished, I start a new activity (of the same class), and instantiate a new workflow (of the same activity).

For instance, my class DoSomeJobClass asks user to scan several items, once they are all scanned, I show a toast message, and start a new DoSomeJobClass to initiate a new scanning task for user. I acquire the scanner resource and perform the related initialization work in onResume() of DoSomeJobClass, and release and de-init the resources in onPause() of DoSomeJobClass.

 

Any hint/suggestions on what could cause the above exception?