In particular, plenty of cafes/institutions/whatever popup a window to let you login/pay for internet. This window pops up as soon as I'm connected to the network. Inevitably, if I just go to a website in my browser itself, the same screen will come up, and for some reason in the past I've had trouble just using the popped-up login. In particular, when I login, even when I get a success message, I don't seem to be logged in.
I'm not interested in debugging the login problem, but I would like to prevent the popup windows from appearing. How can I? I'm on a Mac running Lion.