There have been discussions on the site before whether electronic devices interfere with aircraft systems or not. I just got this link in an e-mail from the Hawaiian flight safety office.
http://www.aero-news.net/index.cfm?printable=1&ContentBlockID=cd752a3a-584c-4ba3-bbed-93555f2b2ade&
http://www.aero-news.net/index.cfm?printable=1&ContentBlockID=cd752a3a-584c-4ba3-bbed-93555f2b2ade&

......I've never had any problems in nearly 25,000 hours aloft in mostly steam-gauge equipped aircraft w/ needles moving/not moving/radios jammed/freqs blocked ... etc., etc. Military or civilian.