I've been trying to fix a problem with my display, but my biggest road block right now is that I'm having trouble figuring out quite what the problem is...nothing i have tried has seemed to work, but i don't know if it's because i'm not doing it right, or because i'm using a solution to the wrong problem... I have my my knoppmyth box hooked up to a tv. I would tend to describe the display as "grainy," except that everyone else complaining of a grainy display has had really bad video, and those that have posted pictures look much different than mine...my video looks a little grainy if you look closely, but it's not that noticeable. It's mostly evident when there is a lot of the same color on the screen, such as on the mythtv menu's...it's kind of pixelated i guess. If somebody could just steer me in the right direction, I would greatly appreciate it. Thank you.

Sounds like you need to modify your modeline.
Depends on a number of variables to get the right one.
The most important what part of the world are you in? What are you displaying on and how are you getting your signal to the display device?

For me, in the UK we have PAL-I (720x576) so my modeline needed to work with that. I also am using a CRT TV at 50hz as per PAL-I standard. I am also using S-Video. So for me, I had to define my modeline, how I was outputting it and making sure my refresh rates were corret.

If your TV is some huge 50' digital display you will need to know what your native resolution is etc.

All the information is around and about if you search for XF86Config-4

sounds like you're using 16bit colour instead of 24bit. In your /etc/X11/XF86Config-4, find:

Section "Screen"
[...]
DefaultColorDepth 24 <--- this should be 24

My DefaultColorDepth was in fact 16, which made me really happy because i thought it would be the easiest fix I ever had to do...But, unfortunately, changing it to 24 made no difference. I've been working on the modeline for a few hours now, guessing at some values since I don't have the specs for my tv (the company doesn't have them online either)...but so far, i haven't been able to make any difference. While working on it though, i found that if i had no modeline, it looked the same...is it supposed to work with no modeline at all?

There are a bunch of builtin default modelines. You can see these if you look at the X log file /var/log/XFree86.0.log.

ah, ok. that makes sense. thanks.