The number of PlayStation 3 customers who have been affected by Grand Theft Auto IV system freezing may be happening to a "limited number" of the user base, according to Sony, but that doesn't mean it's not a very serious problem. The proposed fix, as suggested by Rockstar technical support, is also serious. A twelve step, system feature encompassing process, according to a report from GameSpot.
The extensive and unconfirmed fix requires that one disable auto saving, one's internet connection, DualShock 3 vibration, the PS3 information bar, and Media Server functions, as well as deleting the PS3's install files, save files and internet cache. It's comprehensive, to say the least.
We would definitely suggest letting us know if you're affected by the issue and if you find the suggested fix to be successful or unsuccessful. In the meantime, we wait for an official, certified fix.
Take-Two suggests PS3 GTAIV fix [GameSpot]