I just completed the upgrade to v3.00, from v2.00. I did press the reset button after the upgrade completed. I did not have to re-enter my WUnderground information, but I did have to re-calibrate the relative barometric pressure setting, which had reset to the default.
The Observer found the outdoor station right away, and seemed to log back into WU right away, too. Like @billybob, I'll keep an eye on it for a while and see what happens.
Tom
KMDQUEEN13