system freezes for 0.x seconds in COD4 MP with my new build pc help..

I've been looking for a lot of threads and tried many solutions... but it still can't help, i've even contacted activision and they cant support me...
my computer specs are no oc all normal...

PSU : Delta server power 550w, +12v1 has 18a, so both mades a 36a, i think it's enough for the card, only 1 dvdrom, hdd - maxtor 320gb 16M,
Windows XP Professional (5.1, Build 2600) Service Pack 3 (2600.xpsp.080413-2111)
P5K
BIOS Date: 11/26/07 19:42:38 Ver: 08.00.12
Intel(R) Core(TM)2 Duo CPU E8400 @ 3.00GHz (2 CPUs)
2048MB RAM (Kingston 2x1GB 6400/800)
DirectX 9.0c (4.09.0000.0904)

ASUS EN9800GTX TOP
512.0 MB
Using a 22" monitor
Driver : nv4_disp.dll
Driver Version: 6.14.0011.7516 (English)
DDI Version: 9 (or higher)
Driver Attributes: Final Retail
Driver Date/Size: 5/2/2008 22:46:00, 6108160 bytes
WHQL Logo'd: Yes
WHQL Date Stamp: n/a
VDD: Mini VDD: nv4_mini.sys
Mini VDD Date: 5/2/2008 22:46:00, 6554496 bytes

Sound Blaster X-Fi Xtreme Audio (bought to test if it was the onboard sound card problem... but still happening)

3dmark06 i've scored 13.5k

my problem is when i'm playing cod running with everything on (aa x2, trillinear) except vync and dual vid cards are turned off 1680x1050, while i'm playing the game sometimes when a grenade explodes or gun fire happens, the sound or let's say the whole system coz my monitor/mouse freezes/lags as well, for 0.x seconds it's a very fast freezing then back to normal.. it's very annoying.. i don't have crysis so i can't test this kind of issue on that game... but in WOW/CS:S and DOD:S i dont suffer this things..
i've tried to buying an sound card.. but it looks like it didn't solve the problem at all... all drivers are up to date
my fps sometimes drops to 6x on that new map creek
thanks in advance and sorry for my crappy english..

i would get a better power supply the minumun requirements on the box are minimum u want more to have better results

Have you tried playing the game with 1 card? (what card do you have anyway?), could be micro stuttering?

It's just this:

Got me confused.

I have the exactly same problem as ppv.
This even happens in cod2 as well.

The only hardware I havent tried to change in hopes of correcting the issue is the vga, mb and psu.
Tried every driver/bios/os combination there possibly is.

I was thinking about trying with a pci soundcard, but seeing as it didnt solve the problem for ppv, that wont be necessary.
Audio works perfectly in windows with no stutter whatsever, so I dont think its the audio codec.

ppv: what kind of p5k board do you have?

my specs:

asus p5k-e/wifi
q6600
corsair hx 520 psu
xfx 8800 gts 320 mb
2 samsung 500 gb hdd
1 nec sata dvdr
3x 8cm fans
no overclocking

From what ive been told, my psu should be strong enough.
Anyone disagree?

have you solved this problem cause its happening to me too in cod4 and cod2

but only when i play them online

um ... the look it has to me ... its could be a latency problem ... Especially if it happens only online ... try to turn off everything that taxes your internet connection that u don't need to play the game ... Anti-virus or team speak 4, MSN, all those annoying things .. run only the game... also .. ( there was a time i was doing that error) in the Ping/Latency column .. you wanna take the smallest number there is ... (I truly once believed the bigger it was, the better ROFLMAO And i wondered why my game ran so well in single player and not on the net lol)