At the end of Stargate: Atlantis' season one episode Childhood's End
McKay reactivates the EM shield to continue protecting the villages from the threat of the Wraith.
Given that the puddle-jumper is deactivated by the device, how
are they going to fly it back to the stargate if the shield is now activated once again? You can even hear the puddle-jumper powering up at the end of the episode.
I don't know if the answer would involve speculation, since the answer was not apparent to me during the episode, but I would be interested in either fact or speculation.