I have the same problem too, out of all the freezes i took ever since getting this game from day 1, today the bugs have finally corrupted my save file which is also a first for me to ever happen. I will literally list all the freezes that usually occur to me when playing the game.
■Sometimes freezes during a loading screen when trying to join a multiplayer game
■Rare cases of freezing in the midst of getting relocated to the Meet Up
■A random freeze when playing multiplayer for a long period of time, these kind freezes have became more harsh and frequent after the last patch that promoted the Ultimate Speed Pack DLC. This is the most common freeze and will most likely be the one that will corrupt your save data compared to other freezes. This one is garunteed to happen to people who love playing on multiplayer non-stop. How often it occurs usually varies but it can be as frequent as happening within the time-span of a speedlist or 2
■After you become a Concours player (aka gotten your golden license plate frame) a freeze will happen at the end of a speedlist when tallying up results. This freeze can only be avoided by playing your very 1st speedlist from the very beginning (seeing the list of events a speedlist will host for you) prior to starting up your game. This gives concours players a burdening practice of backing out of online games frequently until the conditions as mentioned have been met.
With all these rampant freezes it has became harder and harder for me to spend time with online friends since every hour of the day (not exaggerating) I have to force shutdown my PS3 from a freeze, let it does its file restoring which takes a dreading wait of 5 minutes to finish, then i gotta go back online and do the practice of backing out and joining in until my 1st speedlist is one that is about to start instead of it currently being in progress. I finally get past all that, then it will freeze again, and the cycle starts all over again...
Please fix these freezes, i have actually been very patient to take all these freezes and today it has gotten the better of me as i literally had to force shutdown my PS3 from freeze probably 9 times in one day. I miss out on too much of the action and fun with my friends as well as losing my 100% single player completion because of this