Well if you have come back again ......?

I think it might be a corrupted game save.

Save all your game save data to a USB stick, this includes all your Ghost SL &TT saves [If you want to] ...you can fit it all on a 500mb USB stick.
Same goes for all you other games [multiple USB drives]

Then checkout this link.
http://www.ps3trophies.com/forums/tr...ter-speed.html
Do what's recommended ...then report back if you are still suffering problems