Since ~September, I've had to unplug the power cord about 5 times, also hold down the power button to get a reset about 4 times. No data loss yet, no need for any other fancy maintenance stuff (who knows though, maybe a reinstall would stop the freezing).
The freeze point appears random in location and ps3-On time.
The case is not hot, and the fan is quiet but operational.
The PS3 is ~11 months old, ~100GB free space, used enough to get A&BSpec lvl40 with a bit over 100,000 miles +online freerun hours...
AFAIK, this was not a problem before I changed from a DFP wheel to a DFGT wheel
It's pretty straight forward, one of the following is the problem:
PS3 (hardware or software)
GT5 (Update)
DFGT Wheel
PSN Network
If I get pissed off enough, I will try to eliminate PSN Network and Wheel from the equation...