I don't use T-Mobile Hotspots often. However, I have been using it while in Seattle this week. It was the first time I used the Hotspots since switching my Macbook to OpenDNS supplied DNS servers. Unfortunately, you can't get to T-Mobile's proxy on the inside of their network (makes sense) when using OpenDNS servers. So, I removed the OpenDNS DNS entries for now. I should have created a new profile but was in a rush to get things working and didn't think that far ahead :-)