So that would mean it tries to load X, but throws you back into the console? IF that's it, then your drivers aren't working. I sugest you revert to your original setting, then download the drivers using Synaptic(do a search for nvidia if you've got an nvidia card, or fglrx for ati, make sure you've got the correct version also. You can check the version you need under KDE Control Panel under Release on the front screen. Most likely it's 2.6.10. Then check
here under the X configuration section. Before editing
BACK UP YOUR XF86Config-4 using (in root mode of course)
Code:
# cp /etc/X11/XF86Config-4 /etc/X11/XF86Config-4.bak
When you screw something up, you can revert your changes by simply removing the .bak extension by
Code:
# cp /etc/X11/XF86Config-4.bak /etc/X11/XF86Config-4
Also, i take now responsibility if you blow your computer up or something...
Good luck!