The captive portal things does work, at least with the Telmex hotspots in Mexico.
One other screenshot, your ip settings appear when you're connected to your wifi network and you tap your same connection. How does that look? I assume you don't have a 1.4.5 device (Pre/Pre+) to try and connect to the same network, do you?
I really think you should send a feedback message to Palm as it appears to be a bug in the captive portal detection algorithm.