I have recently upgraded to the PV after having a version 1 for almost a year. During the past year I have flown the P1 many times in my back yard with no trouble receiving GPS signals sufficient to maintain constant green LED indication. Now, in the same locale, the PV will slip in and out of GPS mode -- changing to flashing yellow from flashing green -- with flight characteristics expected of ATTI (or non-GPS) flight. Even hovering in one spot this can happen. It comes and goes, and is indicated on my iPhone as GPS has insufficient number of satellites (I think -- it's too small for me to easily read in outdoor light). My yard does have numerous tall pine trees all around, and when I go to a nearby park with more open sky the GPS mode on the PV is entirely stable. Also, if I fly high enough to clear those trees, the GPS becomes more reliable with height. So, is there any plausible explanation of why the GPS receiver on the PV might be weaker than the one in the P1? Can anything be done to improve GPS reception on the craft? I live in heavily wooded country. Anything I could do to improve GPS reception around trees would be a great help.