GPS and Mobiles



Has anyone had experience of a Mobile interferring with (or worse, ZAPPING) a GPS? I have read and heard of some problems but can not find any real information. Is it just hearsay or is it now a recognised threat?
My own Phillips Mk9 has recently lost its ability to pick up satellites and it has been suggested that its microcode 'knickers have got twisted'! Is this likely to be terminal or could a new microcode load fix it for me? I plan to return the unit to Leica (took over from Phillips) but if a re-load does not work then it will be 'curtains'. If Mobiles are a problem, how close is the danger area?
Finally, why is this problem not more fully broadcast? Could it be that the manufacturers are happy to sell us new units and are keeping quiet??