I cannot comment on the CRJ issue since i'm not familiar with the type but i had my phone accidentally on throughout the flight at least 5 times in the last 10 years (A320/A330/A340) without any nav problem and also in my current outfit we have gsm/3g data/wifi enabled above 20.000ft and no fault was ever spotted. (Long haul, widebody operation, A330/A340)