Sorry to say this but you might need to re-download all of the updates again and reinstall them as it sounds like something got corrupted. It's never happened to me but I've read countless threads by people with the same problem.
Follow these instructions step by step and you should be able to get it running:
http://community.us.playstation.com...smo-6-Update-Installation-Error/td-p/44861222
Don't interrupt the process once you've started it as you'll have to do it all again.