Is there a way I can revert to the last kernel I had on here? The kernel update has just made things more difficult for me. I can't install my nvidia drivers, KDE and firefox have started crashing (not much but enough), etc - etc. Please help.

You probably have a backup of the old kernel version:
# cd /boot
# ls -l vmlinuz*
There should be at least two files: The kernel itself (vmlinuz-<version number>) and a link to the current kernel version (just vmlinuz). If there is a third file, it will be easy to restore the defaults:
# rm vmlinuz initrd
# ln -s vmlinuz-2.6.11.4-20a-default vmlinuz
# ln -s initrd-2.6.11.4-20a-default initrd
You appear to be using SUSE Linux 9.3; these are the names of the default files which on that distibution. If you are missing these files, try to reinstall the old kernel with YaST first.

Hope I could help,
mschutte

Thanks a lot for the tip. I'm working on my own Knoppix CD right now. I'll try your suggestion later today and post the results.