seems that ur PS3 might be overheating.. Does it go extremely loud ( turbo fan ) during ur games? if it does, its a sign that u should change ur thermal paste inside. Or else u might have permanent YLOD. 

Or maybe u placed ur ps3 in a area with little ventilation?
Mine is the same set as urs , 40gb phat.

Here's a hint before ps3 gonna YLOD , Fan often goes super loud like vacuum.. If it does that , Time to change thermal paste  . Changed mine recently , posted a little guide on preventing YLOD few pages back..

After changing thermal paste, everything silent. no more crazy loud fan even if im playing whole day ( 8 hours or so ) .. Trust me, u dont want a fried GPU / CPU unit in ur ps3. 

thermal is a medium to add more contact between core (cpu / vpu / gpu) to the heatsink. We knows that the heat sink interface may have some pores / hole. By using thermal paste, it can covered all the holes. So core will have more contact to the heatsink. Then more heat can be transfer to the sink. It will makes the core cooler than not using a thermal paste. But we still need the passive (heat sink) and active (fan) cooling.

nice to hear that u'r wifi problem solved

actually there already a thermal paste applied in our PS3...but it will dried after sometimes of usage. That's why some of us have solved their problem by replacing the paste. Since u are in air conditioning room, so the environment temperature is better than most of us who don't have an air cond 

my suggestion?just make sure u'r fan is 100% working...clean all the dust from intake / exhaust hole and make sure nothing block the ventilation hole (intake / exhaust)

fan inside the PS3 itself

you cant get nat 2?have u try putting ur ps3 on dmz?

NAT type 3=u are using router
NAT type 2=u are using wi-fi
NAT type 1=u are using wired connection (direct to modem)

u are using wi-fi but get type 3?i also used wi-fi but directly connect from the line.get type atm.

i got 2 modem atm.both are TM's router.when i need NAT type 1 i'll use wired modem (phone line-->modem-->ps3).if i want to used laptop & ps3 together i'll switch to wi-fi@NAT type 2 (phone line-->wi-fi modem-->laptop & ps3).thats how my setup is.

you can get NAT 2 with wifi

hope that the router won't block certain ports (hence you get NAT 3)

well depends on the router and ps3 settings...

it is possible to get NAT type 2 on wi-fi...

u can try DMZ, put ps3 ip address there

im using wifi tooo...before dmz got nat 3, after dmz got nat 2, all game play online no problem...

to dmz, first manual configure your ps3, then put in static ip, mine i put 192.168.0.140, you can put anything u like...after ur ps3 has stattic ip...go to ur modem admin page, mine is dlink so its 192.168.0.1, your might be diff because diff brand, maybe 192.168.1.1, then go to wireless setting, enable dmz then put the ip u set in ur ps3 there....

hope u understand my instruction..hehe....

i also facing the same problem....
mayb ps3 not supporting belkin's routers....

oh...ok i really get u wrong
coz i also facing problem connecting my ps3 using wireless thru belkin's router...