AlunS

It happened to mine every now and then. I suspect it's the battery contacts which get a bit loose, and then a bit of a knock or other shock can momentarily cause a brief lack of power. I just bent them out a bit with a screwdriver to make the batteries a slightly tighter fit.

I'd put money on it I'm out tomorrow on a hike too, so I'll check it out as well and come back with some figures. What software did you use to analyze the track data by the way?

IIRC for the basic yellow etrex, the Camo and the Summit there were essentially two different hardware versions. The latest software updates for these models were unsuitable for the older hardware revision, so you were stuck with the last software created for the older h/w revision which is 2.14 unfortunately.

The registration between reality and the satellite / aerial imagery is very bad in places, so 17m is doing pretty well, I'd say.

It's better than what a lot of people have reported with the 2.30 version, but still not quite right when compared to the reported distance computed from the track logs. It was supplied with that version of the GPS firmware I believe, although I'm not quite sure as I ran Webupdater as soon as I got it set up.

Yes, I've noticed exactly the same problem. I went on a hike last week, that started and finished at about 200m and went up as high as 925m with a few other small ascents in between. I'd have guessed at about 900m of climb altogether, but my Vista HCx said 550m or thereabouts! The altitude plot on the unit looks OK, and the altitude plot displayed in OziExplorer from the downloaded track looked OK as well. I'd be interested in what reply you get from Garmin. My software is at 2.50 and GPS at 2.40.