I get no connection to internet, when i try to connect by wlan0 and wpa-psk with an hexadezimalcode to internet.OpenSUSE 12.1 has no problem with this by the same values.
I found yet a solution for this problem by myself. I installed to my kde3-desktop also the xfce-desktop. And there I could set all values and keys into the network-manager. In xfce I got an encrypted connection to internet. When I switched back to kde3, the encrypted wireless connection is also running. It is impossible in yast to get an encrypted wireless connection. It seems to be a bug, because there is no access to wpa-supplicant. So, I had first to search and study, how i can use the networkmanager, because in kde3 is no panel-icon for networkmager of xfce (It seems the same as in kde4). But now it works and that is important.