Fist off: I tried out the Gnome 3.12 repo for openSUSE 13.1. It didn’t work (gdm would just show a black screen) so I remove the repo and downgraded again.
So I know that this is my fault. But I still hope there is an easy way to fix it 
Basically all fonts (except for Firefox for some reason) look like blocks.
http://gothic-reloaded-mod.de/upload/2014-05-07.png
Am I missing some packages, or is the configuration screwed up?
I am grateful for any kind of help
Looks like the problem is related to pango, the text rendering engine that GNOME/GTK uses.
Did you downgrade all pango packages to the standard versions again?
rpm -qa | grep pango
Maybe you just need to re-create the pango modules cache:
sudo /usr/bin/pango-querymodules --update-cache
and if you’re on a 64bit system, this in addition:
sudo /usr/bin/pango-querymodules-64 --update-cache
If there are any errors, please post them.
You are right. I also started to notice that only GTK-Applications suffered from those font issues.
And recreating the cache did the trick. Thanks man
I think I’ll just wait for 13.2 and stay on gnome 3.10 (**** curiosity^^)