Comment 6 for bug 310353

I suspect the theory behind this is that in stock X there's no GUI way to change the DPI value, so GNOME provides an override in case your X config is wrong (under the theory that you're not likely to figure out how to fix it in xorg.conf if you didn't get it right in the first place). Since SUSE does provide a GUI way to change X's value, the argument falls apart a little (although the GNOME setting has the advantage that you don't need to restart X after changing it).