LCD Pixelation :(

so I did it, broke down and bought a new 19" Acer Lcd monitor 8ms. everything seems to work just as hoped, except for a pixelation effect i get when viewing video files (avi, mpeg, divx, etc.).

I understand that a fast monitor, like this one, rids the user of "ghosting" effects. but shouldn't it also help with pixelation? or am i off base? could it be my old video card? I have an old Dell system (prob. 5-8yrs old) (i think pentium 2) with the original video card. Oh, and the new monitor is hooked up analog, not DVI (it has both connections).

On my old CRT, these files looked perfect. Any suggestions? if it's the monitor, i can return it, but i don't feel like risking it since i have no dead pixels or any other problems.

I also get pixelation from streaming video feeds. Anyone else have this problem?