Slight lightning pixelation while in movement - gpu or monitor?

Hello,

First my system specs:

Saphire HD 7850 OC (at default OC) With CCC 12.4
i5 2500k (turbo enabled, i.e. 3.7 ghz while gaming)
16 GB Corsair Vegeance @ 1333 CML16GX3M4A1600C9B (but can activate XPM for 1600)
Maximus IV Gene-z/Gen 3 Motherboard BIOS - 0402 (first released BIOS)
Blue Caviar WD 500 GB
Seasonic Semi Modular 620 W PSU

Monitor: ASUS VS 228H-P

My system is brand new and I used to have a LG L227WTG-PF Black 22" 2ms Widescreen LCD Monitor 300 cd/m2 10000:1DCR with HDCP Support, which I had to sell because I moved countries... anyway I have read that monitor was beyond excellent.

Now to the problem, I don't know if I never noticed or not, but I have been playing Diablo 3 and there are quite a few light sources than stand out in the grayish environment, what I notice is they look perfectly crisp when my character is standing still, but when I move my character if I pay attention to the light sources they become slightly pixelated, I can see a very tiny mesh of pixels in them.

I though it might be a problem with the game but then I tried Guild Wars because there are some flames in the login screen again without moving my mouse they are crisp, but when I started dragging my mouse around I noticed the same thing!, although I had to get really close to the monitor this time since it seems to be way more noticeable if the surrounding pixels are darkish/greyish.

I am not sure what this is, or if this is actually just normal I am playing with an HDMI cable at 1920 x 1080p. It is kinda noticeable at times in Diablo 3 though.

I am not sure if this could be a problem with the GPU, the drivers or perhaps the Monitor which has a 5 ms response time.

Can anyone please tell me what is happening or if this is normal?

EDIT: Upon even closer examination (about 1-2 inches from the monitor) If I am moving around I can see the tiny mesh in everything, it is not the same mesh I can see standing still (the normal 1080 p mesh), this one is more noticeable. It is just more noticeable on lighting, and it is sometimes noticeable from a normal distance (about 2 feet) on diablo 3 lightning.