Graphics hiccup?

Hello. I've an interesting problem going on. I've just reformatted my computer and reinstalled windows and world of warcraft. Updated my video drivers on my 2 Nvidia 8800GT cards

Not installed windows updates yet, still in the process of getting things. Anyway when I play WoW i'm getting an odd sort of hiccup. Its not a stop or a freeze, its a berely perceptible like....slowdown? I suppose you could call it. I also seemed to notice it when I was using msn. Funny as it sounds, I held down one of my letter keys and let it fill the window, and again sometimes I could see a berely perceptible hiccup.

Music and videos play normally without incident on my system. I cant seem to tell yet if its in any other games but I suspect it might be.

Wondering what this could possibly be, its a clean install on a Q9450 Quad core with 4 gigs of ram, using windows XP SP2. Any questions or comments or advice would be greatly appreciated. I know I havent described it well, and other people may not notice it, but I notice it, and its bugging the hell out of me lol

 

Very sorry for posting a second time. I know there are rules about bumping, but I for the life of me cant seem to locate the edit button.

Anyway I wanted to add that I see the most indication of this slowdown or system lag when i'm playing a game like wow. I'll play in windowed mode, and then try to start up my web browser, and notice it struggling a bit. Or i'll have GPU-Z on, and have it set to refresh in the background, and get a more persistant...jerkiness in a rather predictable fashion. If the game (or another game) is closed its not really something noticable, but I wouldn't go as far as to say it only happens when gaming. I also don't see any large CPU or Ram use spikes when its occuring.

I'm running an Asus Nvidia mobo (sorry I don't have the number right on hand), with 2 8800 GT cards in SLI, and a quad core Q9450 CPU and 4 gigs of ram, on windows XP SP2. I reformatted my PC due to a virus, wasn't noticing this problem before my reformat. During the reformat I used the windows recovery console to reformat my PC with just Format C: and then I did a quick format during the actual installation so I may have done it wrong, I also didnt install the SATA/Raid drivers from my chipset disk, as I dont have a raid, and wasn't sure if they were necessary. I'm not particularly skilled at this kind of work =(.

I've run Defrag, and Chkdisk on my harddrive, which found no problems as far as I can tell. I'm also looking at possible software conflict. I have AVG Free 2011, and Logitech Gaming Software 7.00.291 for my G19 keyboard, those are 2 major software updates I didnt have before I reformatted.

Again, sorry for double posting, would be happy to edit if I can find the button, and I do really hope someone out there can help me with this situation as its getting quite aggravating. If there's anymore detailed information I can provide please let me know