Random Game freezes...is it my PSU?

hello, im new here and i understand very little about hardware but i really need any advice u guys can give.

i bought a new rig 4 months ago and ive been having random game freezes in ALL games i try to play. sometimes i play for an entire day and no freeze, somtimes it happens many times in a single hour. everything just stops and the sound starts to loop, all i can do is hit the restart button. this is my setup:

intel core 2 quad 6600
evga9800 GTX
2 sticks of kingston DDR2 (each 2 GB)
thermaltake TR2 RX cable management 500W

ive been reading up on power requirments and it seems to me my PSU might be the problem since ive already tried everything including driver updates bios update, and memtest. my PSU has 2 +12V rails with a max load of 15A and 16A. i really dont uderstand most of how this all works, so plz guys if u can keep it simple and tell me:
a) is the problem my PSU
b) what thermaltake brand PSU must i buy that would be enough to comfortably power my system and not cause problems

thx in advance for any help u can give and srry for the long post.

I have a 600w thermaltake psu for a XFX8600gt videocard and M2N32-sli mobo setup and have no issues so far (1+year old system)

If u overclocked the system reset the bios settings to defualt

I would also check the voltages of your stuff e.g make sure that your ram and cpu are running in the recomended voltage range. if they are set to auto i would configure them manually then use prime95 to test the systems stability

edit
as Proximon said it could be an overheating issue. Play the games with an open case to see if it freezes. Check your temps also using speedfan or everest and post them

15-16 amps is a little light on the 12v rails. Check your temps, also, check to see how hot the air is without using 3D, run 2D for awhile, then feel the temps from your psu fan, then run 3D and see how much hotter it gets. It will be hotter, but if the psu is heating because of not enough power, itll be real hot. What else do you have on your system? Sound cards, extra fans, dvd writers, HDDs, modem etc. All those add up, its either heat or power, as both take time to build up. Just remember, low power from the psu causes heat

hi thx for replies
i dont think its heat cause sometimes it happens 5min into a gaming session also itried using the evga precision tool and pushing fan speed up to 100% but that didnt help. also it doesnt seem to to change wether im playing with the air conditioning on (in wich case the room becomes freezing) or off. i will download everest and get back to u with the results.

other than the hardware i previously mentioned i have 1 HDD and 1 dvd writer and the fan my case came with (case is a thermaltake soprano RS) sound card and network card are the ones built into the mobo.

concerning the mobo and soundcard drivers i previously had an asus p5kdeluxe wich is now dead due to a botched bios update. but i remember that i had updated everything on that board and the freezing problem still persisted. on this board i havnt updated the drivers but ill try that.

i dont overclock my machine and ive never even entered the bios so im assuming everything is on default. honestly im reluctant to mess with voltages and stuff after the tragic loss of my first mobo.

its not a virus cause it happens on fresh formats that havnt even been connected to the internet

i kinda have to go for thermaltake cause they are the only readily available brand were i live + i think i can swap in the psu i currently have for a better one and pay the difference.

if all else fails would the thermaltake tough power 750W be good enough for me?

thx for being patient guys

You still have not told us you temps, what are they?
Track you temps for a few days, CPU, Video, motherboard and ambient.
Especially get your temps when things hang.

and these are the values from evga precision:

GPU temp: 60 c
Core clock: 675 Mhz
Shader clock: 1674 Mhz
Memory clock: 1102 Mhz
Fan speed: 41

ive noticed that 60 c is the temp the vga maintains itself at if i dont mess with the fan speed.

after a 1 hr wow gaming session, didnt freeze.
Field Value
Sensor Properties
Sensor Type Intel QST (HECI Driver)
GPU Sensor Type Driver (NV-DRV)

Temperatures
CPU 56 °C (133 °F)
CPU #1 / Core #1 51 °C (124 °F)
CPU #1 / Core #2 46 °C (115 °F)
CPU #1 / Core #3 51 °C (124 °F)
CPU #1 / Core #4 49 °C (120 °F)
GPU [ TRIAL VERSION ]
Temperature #2 48 °C (118 °F)
Temperature #3 76 °C (169 °F)
Temperature #4 73 °C (163 °F)
MAXTOR STM3500320AS [ TRIAL VERSION ]

Cooling Fans
CPU 1106 RPM

Voltage Values
CPU Core 1.15 V
Aux 1.24 V
+3.3 V 3.30 V
+5 V 5.04 V
+12 V [ TRIAL VERSION ]

If you look in the forums there are loads of threads on problems with the 9800gtx gpu fan being stuck on 35% regardless of temperature (driver related)
http://www.evga.com/forums/printable.asp?m=319984
http://www.evga.com/forums/tm.asp? [...] y=&#328321
(use COD4 rather than WOW to stress your card)