I refreshed the 201 Software page on the Garmin website earlier this evening and it had finally changed - v2.70, the last update from 2007 had disappeared and the only link was to Garmin's WebUpdater software which automatically checks for updates....
I've now installed WebUpdater on my laptop and connected my Geko, and it's busy downloading v2.90 onto the unit, which claims to sort out the problem. As soon as it's finished updating I'll stick the unit outside and see how quickly it gets a fix.
Post update to 2.90, the unit just went through a very cold start, starting from a sky view showing no satellites (and probably not helped by it last being used in Norway 10 days ago), it took about 4 minutes to find several satellites and read 4 of them, then just when I expected it to give me a position it went blank and started the whole acquisition process again. About 3 minutes later it had 6 satellites read and an accuracy of 6m (plus my altitude spot on). It also shows the correct date and time - hurrah!
Hopefully it'll behave better from now on as far as acquisition goes, plus Mapsource might be happy to download the recorded tracks again (it wouldn't with the wrongly dated ones, but fortunately Quo still would).
Bumping this as I have a Geko 201 with this software problem but I don't have a data cable compatible with the unit.
Has anyone got a link for the relevant cable? I looked on Amazon but there seemed to be a few customers complaining that the cable advertised as 201-compatible was nothing of the kind.