Explorers not rendering CSS properly?

First time posting, but I've been reading here for quite sometime and would like to thank everyone for this awesome community of knowledge. Hopefully that intellect can continue with this one. I'm normally pretty adept at PC issues, but this one on a client's computer has me scratching my head.

It appears as through my explorers (Windows and IE) are not rendering certain CSS aspects correctly. It looks as through it is ignoring cell fills. I see this on any webpage or application that uses CSS. I've included a screencap of MSN and MSE to help.

I have already made sure that the computer is virus/malware free. Have run HijackThis, MBAM, ComboFix, and have checked JPEG, GIF, and CSS registry portions with no luck. My next step is a repair install then on to full reinst, but I'd rather not for obvious reasons.

The computer is as follows:
Dell Dimension 4600c
512MB RAM
Intel P4 2.8 GHz
Windows XP Home SP3
IE8

If you need any further info, please let me know, and thanks in advance.