Blank Laucher caused by firewall/proxy?

Hello,

Did a fresh install of minecraft on my laptop, and tested it, before going on vacation to LasVegas. Once here I connect to the hotel (Stratosphere) wireless, and start the launcher only to get a blank screen. The launcher never (waited 10 minutes) draws anything to the window. disconnect from the wireless, and the launcher almost immediately comes up in offline mode.

Now I never really expected to play online, and I realize there is no fixing the Hotels broken Wifi/Firewall/Proxy or whatever is causing this. I do think though the launcher should be able to detect if the communications requirements are incomplete, and drop to offline mode, and/or log a message as to what part of the communications are incomplete.

Testing shows ports 80 and 443 work, not sure what other ports the launcher needs.

Thanks