My ps3 has been freezing quite often recently and it is only a year or two old. I have it in my basement about five feet from the wood stove. Could the heat from the stove be causing it to freeze? It gets really hot down there cause the stove has to heat the whole house.
I run a fan heater next to me which is next to my PS3. When on long gaming seshs it doesnt freeze often but does happen in the home menu. I do believe this is because it does get too hot. I would suggest moving it to a cooler place, personally i check the temp with my hand every now and then to see if its ok. Overall ive never had problems with freezing unless its too hot or my internet is being raped so its super lagging.