Just a follow up on my personal experience using iBarcode as relates to Stop/Start executed repeatedly in less than 5secs that results in a crash with the camera showing a black box. I have remedied by not allowing the user to click scan while the code is processing under the Detect event. Secondly I don't Stop the scanner unless it is idle for over a minute but I do simulate the Stop behaviour by using a boolean to determine if to allow entering the code in the Detect event.
Using both the methods above appears to be 100% uptime without any crashes.