Well being that I just installed Suse 9.3, I'm still getting familiar w/ the WPA gui. I got the WPA supplicant to work but only via command line because I've used wpa_supplicant in earlier versions of Suse. You need to create your .conf file also.
wpa_passphrase <essid> <passphrase>
enter the output of that to /etc/wpa_supplicant.conf
then just wpa_supplicant -B -i wlan0 -c /etc/wpa_supplicant.conf
it worked like a charm. If I figure it out on the gui side of things, I'll let you know. Hope this helps