Slackware 13, Gateway NV52, Atheros AR928X - 168c:002a (rev 01)

After startup, I can get connected to my router using:
ifconfig wlan0 up
wpa_supplicant -B -Dwext -iwlan0 -c/etc/wpa_supplicant.conf
dhcpcd wlan0
I know it works, because this is how I'm posting now.

However, when I try to set up the rc.inet1.conf file so it will load on start up, I get :
Error for wireless request "Set Nickname" (8B1C) :
SET failed on device wlan0 ; Operation not supported.

Here's what I have set in /etc/rc.d/rc.inet1.conf (relevant part):
IFNAME[4]="wlan0"
USE_DHCP[4]="yes"
WLAN_ESSID[4]=myRouter
WLAN_MODE[4]=Managed
WLAN_RATE[4]="54M auto"
WLAN_WPA[4]="wpa_supplicant"
WLAN_WPADRIVER[4]="wext"

Any help is greatly appreciated.

"Any" help comes:

Just put it into rc.local and forget the rc.inet1 stuff.
What is it good for? Do you have any GUI programs that manage your connection and rely on rc.inet1.conf?

You may even replace rc.inet1 with your own, eight lines long one and get rid of that very long script. Beware: do not forget to set up loopback interface ;-) This may lead to strange behaviors, I can tell you ;-)

The idea of Slackware is to know Linux, not any particular distro. If you know how to set up wpa_supplicant, why learning how to set up wpa_supplicant via Slackware startup script?