The PPC release no longer has the ability to repair an already installed system. Selecting the "repair installed system" option on the Install or Update screen results in a reboot where the boot menu is:

Welcome to openSuSE 10.3 (PPC)!
 
Type  "install"  to start the YaST installer on this CD/DVD
Type  "slp"      to start the YaST install via network
Type  "rescue"   to start the rescue system on this CD/DVD

To see this, these steps are required:

1, boot DVD and enter install at the boot prompt;
2, select keyboard layout;
3, click next on the media check screen;
4, accept the software license;
5, click other and leave the default "repair installed system" selected;
6, click next.

On my G3 iMac, this results in an instant reboot.

As a comparison, when booting the 10.3 DVD (i386, presumably the same happens with the x86_64 release) there is the choice to repair an already installed system given as a boot option.

This presumable replaces the same option that was previously available as one of the other options when performing an installation or update (the other is boot installed system) as using that option causes the system to reboot.