For those who care about not crashing the aircraft they are on
Heed those warnings and don't run your electronics in the plane. Transport Canada has documented cases of pocket calculators screwing up electronics (primarily navigation and communication equipment), or at least so says my brother, the pilot. Also, as he says "I can't cite, but I believe that the bandwidth that GPS operates in is also very, very susceptible to interference. GPS signals are also very low-powered; GPS antenna are correspondingly sensitive..."
Martin, hope that answers your question.
(Sorry, couldn't resist the title)