Ok, let's try doing it from command line.
Take a look at http://home.roadrunner.com/~computertai ... eless.html
There's a simple howto of mine and a link to a more complex howto as well.
To review it briefly. Make sure NetworkMangler--errm Manager, isn't running and won't run on boot.
chkconfig NetworkManager off
Then reboot, because it's a Gnome thing and they're like Windows. Seriously, it seems to do all sorts of other things, and even stopping those things manually doesn't always work, at least for me. I've never investigated it that thoroughly because I turn it off anyway.
Make sure that in /etc/sysconfig/network-scripts/ifcfg-wlan0 it does NOT say NM_CONTROLLED=yes (or anything similar, I might have the syntax wrong.)
Then reboot, be sure to bring the card up with ifconfig wlan0 up.
From there, you can look at the link above and create a simple wpa_supplicant.conf file. Actually, for testing purposes, you can just do something like wpa_passphrase blah blah > wpa.conf (in whatever directory you happen to be.) Then you can check if it's working with wpa_supplicant -Dwext -iwlan0 -cwpa.conf (The -c is the config file, and this way, you can use the test file without worrying about your default wpa_supplicant.conf.