Ok here is what happening. I set my time which is eastern time zone, Gps enhanced on, time format 12 hrs, time zone utc -05:00, units yards, GPS time sync is checked, There is another setting I do not know anything about, which is dms and dm. It is set on dms. What is Dms or dm? Well anyway some times when I turn on my CTX. the time is wrong, so the gps will not turn on or lock on to satellite's. How should all those setting be set?