To the people that cant get the game to load up again after it crashes using the market, and have repaired the beta again, and it still isnt working - Try this: Go to Finder>Library>Preferences>City of Heroes Beta Preferences. Delete the City of Heroes Preferences folder, and try playing it from there.
This is what I have to do EVERY time I reboot the beta AND the actual game, and i've been doing it for months. I'm no tech expert, but it could work.