Could be some pop up screen saying you can't sue us if you use this wifi, click to acknowledge. Something like that. If it's something like flash that the BB can't do, you'll never see it.
Or they could be open as in free of a security key, but actually require a login on a website login screen.
Since you seem to be in the UK, I would say it also could simply be the BB has an issue with the routers. You have to be way more specific about what steps you are trying and what the screens show, wifi icon color, etc. for people to be able to do more than just guess.
Last edited by monkeypaw : 01-24-2010 at 08:58 PM.