I know absolutely nothing about GPS, other than how the only unit I ever ownedsaved a group of us from certain peril in a whiteout blizzard while snowmachining several years ago. So if my question/proposal is silly, justchalk that up to general GPS ignorance. Is it possible that over the course of 16 - 17 seconds of continuous accessa GPS signal may occasional "flutter" or "scramble" in someway? I mean, cell phone calls break up all the time and radar signals canwaver a bit... so could it be that some anomaly in the GPS signals (caused by sunspots,greenhouse gasses, or interference from UFOs) be responsible for theseoccasional glitches? Perhaps this is something that PP and ZO would beloath to admit (if true), but what do the more learned members here think ofthis possibility? TW