Thing is I don’t use gnome and the gnome Yast GTK interface is crappy. How about we switch you to QT, it’s fairly easy.
The gstreamer:
you need to look to change vendor
when you get a error there should be an expert button in the error bos allowing you to save the details to a file and then post it here
[EDIT]
Here is how to use QT in yast
http://forums.opensuse.org/how-faq-read-only/unreviewed-how-faq/400090-how-get-qt-zypper-gui-gnome-yast.html#post1897909