With the above, I think there's a thread around the forums here with a trick to "tickling" these hotspots. You find our your local device IP after connecting with Wifi, let's say it's 192.168.1.5 and the gateway is then 192.168.1.1. You open up the BB browser, Menu -> Go To and type in
http://192.168.1.1/ -- this contacts the hotspot gateway and sets up the association or something...
(I tried to do a quick scan for the thread, not finding it - it's buried somewhere in the Wifi subforum I do believe)