I haven't added anything to YaST sources as outlined in the sticky so I don't have any experience there. I always just download the rpms I need and install from the command line. You've probably already noticed that upgrading KDE is kind of complicated from the command line which is why updating the YaST sources is helpful if you're new to this.
One tip I can give you about updating from the command line is to use the -F option so you'll only update packages that are already installed. If you're downloading new packages that weren't installed originally, you'll get a lot more dependency problems. Example:
rpm -Fvh kdebase3-3.3.2-7.i586.rpm
This command will only update the kdebase package if it's already installed. Otherwise, when you press enter, the cursor will just move to the next line and nothing will happen. I have about 40 files in my kde3.3.2 directory so it takes some time to do it by hand without the help of YaST. I prefer to do it from the command line, but that's just me.
edit: Here is one SUSE mirror in the UK that has updates for KDE.
ftp://ftp.mirrorservice.org/sites/ft...lementary/KDE/