Summary: My fonts are driving me crazy and I think it is due to antialiasing

Details:
I installed Fedora Core 4 on my desktop (uses a NEC MultiSync LCD 1860NX).
The fonts looked blurry so I used xmag to zoom in on them. I could see fringes of
color around the test so suspected antialiasing was the problem.
I disabled antialiasing in Control Center -> Appearance & Themes -> Fonts (I'm using KDE) and the problem went away.

Now I had to install RedHat Enterprise 3 instead of Fedora Core 4 because I have an application that doesn't work with Fedora Core 4 yet. I saw the same problem with the fonts so I turned of antialiasing again but the problem didn't go away this time.

Is there somewhere else to turn of antialiasing or do I have the wrong solution?
I'll send you a screensnap of the xmag fonts if you want to see what is happening.

Some more information:

It looks like a problem with smoothing set to subpixel. When I set it to greyscale, there is no problem. I was able to determine this switching to GNOME and using the font preference tool.

So, my question now is how to change font smoothing from subpixel to greyscale in KDE?
This isn't an option in the control center.