I traveled some 1400 miles over the last week or so. The Navigation worked perfect for the first 3/4 of those miles and then suddenly started the "shut off thing" about every 5 minutes. I tried: 1) Turn phone off and back on. No help. 2) Toggled Airplane mode. No help. 3) Battery pull. BINGO! Fixed it. Is this an Android or a Blackberry EDIT: I was in an area with full 3G and GPS service the whole time this was happening.