Okay, after a few tries, I found the (surprisingly easy) solution:

$: sudo zypper ar -f http://download.opensuse.org/repositories/home:/seife:/arduino/ Home:seife

$: sudo zypper refresh

NOTE: Accept the package/repository key to the level with which your are comfortable

$: sudo zypper in arduino
It does NOT install via the One-Click install from http://software.opensuse.org. The individual RPMs do not install if downloaded from the repository http site.

If you have any security/privacy addons for Mozilla Firefox, the browser will not be able to navigate the links in http://download.opensuse.org/repositories/*

I am trying to find out which addon produces the error. I'll update this thread once I narrow it down.