I believe that Architect is suggesting that the AP is a honeypot. As far as I know, that would generally only apply to a corporate or commercial setting, not residential, but the OP doesn't say which type he was accessing.
Also, I don't know much about IPs, but I do know that sometimes dynamically assigned IPs can misbehave all by themselves without any changes being made (at least not that the end-user is otherwise aware of). Short of resetting the AP, the only thing that I've found to help with this is to reset the laptop by rebooting. Other than that, you could check into the process underlying the assignment of IPs to your device. It's probably something with that, given your apparent certainty that the owner of the AP has done nothing to improve their security.
Of course, you could be wrong, and failure is always an option.
EDIT: Yes, since you're in a residential neighborhood, I'd agree that it's unlikely.
EDIT 2: Unless you're dealing with another hacker or someone of similar skill who deliberately left it open, hoping you'd come along so they could play ball with you and do some counter-hacking.