In a previous article, "Mike Z." said:
6 birds almost full scale in 45 seconds. The 196 had only
2 -1/2 scale open bars after 3 minutes and showed no signs of acquiring
more. I had to leave for work and still no lock.

If your GPS hasn't gotten a full ephermeris data in a certain time (a
couple of weeks I think), it will take 15 minutes to download a new one.
This is true of every GPS unit - it takes 15 minutes to download it
because that's how long it takes to transmit it.

Thus, if you haven't used your GPS recently, it would be a good idea to
turn it on and stick it on your front lawn or car's dashboard for 15-20
minutes the day before you have to use it.

It sounds very much from your description the first time you only left it
on for 3 minutes, so you didn't get full ephemeris, and so the next time
when you did leave it on long enough (15 minutes), it got the full
ephemeris. I bet if you use it again soon it won't take anywhere near as
long.

--
Paul Tomblin http://xcski.com/blogs/pt/
....life suddenly made much more sense, the day I fully grokked that people
are stupid.
-- Frank Sweetser