Well, let's see....

I'm really thinking that it's not enough memory to run KDE. It's not that that's a very big possibility, it's just that everything else (that I can think of) looks like such a small possibility.
  • - see if you have the file /home/user/.kderc;
    - see if there's lots of stuff in the directory /home/user/.kde;
    - boot from the CD and check that the filesystems are okay (but it doesn't work for swap):
Code:
$ sudo umount /dev/hda2
$ sudo fsck -c /dev/hda2
$ sudo umount /dev/hda5
$ sudo fsck -c /dev/hda5
Note that you must not run fsck on a mounted filesystem !!! It will try to warn you if you do, but don't do it anyway. The -c option makes it check for bad blocks before looking at the filesystem itself. Read $ man fsck to see what it does.

That's really all I can think of for now. I'm sorry that nothing jumps up and has a big neon arrow pointing to itself! For me, anyway.

Let us know what you find.

-- Ed