I have also been having some resistance freezing issues. This has been the only freezing issue with my ps3, meaning it never freezes doing anything else. The ps3 never gets too hot. The problem only occurs playing online. One of the online issues is the exact same issue described here, where the game freezes at random points (for me it usually occurs right when I start to play a game). Sometimes when I press the PS button the menu pops up, other times it does not, but I can always hear the "pop up" sound of the menu.
The other freezing issue occurs when I join a ranked game (free for all or team based). Every so often (maybe once in an hour), when I try to join a ranked game, the JOINING box with the rotating star just keeps spinning, and there is no way to get out of it. After about 5 minutes or so, an error screen finally appears telling me I couldn't join for some reason. I must say it is a stressful period during those first few seconds with the rotating star! I guess technically it's not really a freezing issue, but it falls in the same category. I was thinking it could be a router issue possibly, but I am doubting it because once I am in game everything is fine. I did notice, however, that this problem only started occuring after the RESISTANCE update, NOT the 1.5 update. Anyone else getting a problem related to this?