[cruise350]

Do a profile update under menu/settings/about phone/updates. This may help. If you look at the top of Sprint Nav does it say basic gps or something to that effect. It may also be a network issue occurring in your area. This happened to me several months ago and when I called Sprint all they wanted to do was factory reset my phone. It turned out to be a problem with the Nav provider that sprint uses not correctly registering my account as having gps included. Once I got to a new area where the outage wasn't occurring my nav started working again.