I have had similar problems with GPS, aside from battery drain. It won't work inside at all and sometimes not well in a car - line of sight seems to be an issue. Using wifi, I have had good results and can get a fix quickly within 20m. Also what works well for me is using GSM triangulation, 50m is a good fix. On my canoe tour I am going to try only GSM to save battery. Will report my success later.