Another one I have found...
It is hard to replicate, but eventually one gets to it.
If during a decoding process one decides to abort (by the way, NO abort button available!!) the only instinctive way is to press Android's back button. Yes, it does abort the process and brings you back to previous screen.
But if you keep on pressing back button until app closes, sometimes (seldom, I admit) when you try and reopen it, it just shows a blank screen. Killing it from Android is useless. The only way to have it back (I have found) is resetting the TC55.
Has anyone else seen this?