I don't know what the issue is, but if you google you find people complaining of the exact same issues with this game stretching back years. Some people manage to get the game working for a few hours then it starts failing again.
What happens is I attempt to start the game and it offers me the patch, initially it would go to a "please wait" screen for a while then the ps3 beeps 3 times and reboots to the xmb. Eventually it managed to download the patch, but after that the game would stick on the spinning coin load screen for eternity. I read online that some people had success clearing the game data and not taking the patch, but that just resulted in the endless spinning coin for me.
Eventually I gave up and installed Uncharted 2 which was smooth as you like and I played for a very enjoyable hour or so.
I'm going to return the game as faulty later and use the cash to get God of War 3, playing the collection 2 demo reminded me of how awesome playing as Kratos is. I'd love to play Uncharted but I can't be arsed with this crap. Console games are just supposed to work and when they don't there's jack shit the end user can do about it.