[OSM-newbies] Unpredictable Behaviour in Potlatch

[Chris Barham]

On Wed, Feb 3, 2010 at 4:26 PM, Kevin & Ruth Sheather
<mobilesheathers at bigpond.com> wrote:
<SNIP>
> Then, and this is the problem, the map goes back to where I live which is
> about 100 km away from where I am trying to add the track. The only reason
> that I can think of for this strange behaviour is that I added a couple of
> bus stops and a post box in this area.
</SNIP>

Hi, I've had this happen to me before, and the reason for this was
that the edit session actually is placing you at the trace start
point,  because the trace actually starts at home.  The cause was
having the GPS automatically start tracing when turned on, this on a a
Garmin etrex/Legend/Vista with extra SD Card storage maybe, then
uploading the GPX trace from the SD Card.
I had turned the GPS on at home to check the batteries, then switched
it off.  Transit to the mapping location and switched on to start
tracing. My Garmin will store it as two tracing sessions on the
internal memory, however the SDCard GPX version only has one
session/file per day, so the start of the session is at home, with a
subsequent jump to the point where you think you started.  Uploading
this GPX trace (from the SD card - the 'one-GPX-file-a-day' session to
OSM will result in the behaviour described.

I can't tell if this is the cause of your problem, but it was the
cause of the same symptoms for me - hope this helps!

The workaround for me was to transit to the tracing session, and erase
the days external SDCard GPX trace file when starting, it will be
immediately re-created by the Garmin and tracing start from where you
actually want.

Cheers,
Chris
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