It looks like routers with WPS (why are there so many with this rubbish now?) needs to be connected by adding it manually via the control panel (and only _then_ let it search). Trying to search, and then connect, only ends in a useless pop-up about PIN. Even for open networks.

Incidentally, my N800/OS2007 can't connect at all to any WPS router, open or WPA. It doesn't see them 95% of the time, and if it does it can't connect.