I assume you are talking about hanging on the loading screen precisely when it says "loading UI".
This is a common problem for many after the patch- even if you have no UI other than default. The hardest hit actually have their modem reset everytime it gets to loading UI. I'm one of these. Sometimes it'll re-establish connection before the game times out- usually not. It's a super pain.
You can find out more here EQ2 Forum Link
Also just browsing through the technical forum, not specifically that link, will show you many are having a related problem.