Your issue I believe is the same as this one, only with different symptoms:
http://boards.cityofheroes.com/showthread.php?t=222794
Read the above, follow the instructions again, and also send a support request to help.ncsoft.com so it can be tracked.
Manga @ Triumph
"Meanwhile In The Halls Of Titan"...Titan Network Working To Save City Of Heroes
Save Paragon City! Efforts Coordination
Ever since the 05/19 update, whenever I log in, I can maybe move a step, but then my screen freezes. Can't even force quit. I have to do a hard shut-down and restart. Ultra Mode is off. Anybody else having this problem? After a few weeks of the black-death-loading-screen, now this. I suppose I could just take $15 a month and flush it down the toilet instead of paying for a game that won't run. My patience is wearing thin.