Follow up: Debian 5 Lenny WPA on A21m with TrendNet TEW-421PC and TrendNet TEW 452-BRP

I use this from a fixed location. And I use LXDE with auto-login. So I do not like NetworkManager.

Well, it only took me a week to go away from FWSE searches and read the most excellent Debian documentation instead. Kudos to Debian's documentation team, and to the Debian wiki contributors.

Big lesson: You do not need wpa_supplicant to use ndiswrapper as a driver backend. wext is sufficient.

If you want to see what is going on
ifup --verbose wlan0

The following seem necessary, even though both the card and access-point report WPA2 supported.
proto=WPA
key_mgmt=WPA-PSK

If you'd rather use Debian's /etc/network/interfaces ( just do this.... :) ):
auto wlan0
allow-hotplug wlan0
iface wlan0 inet dhcp
wpa-ap-scan 2
wpa-scan-ssid 1
wpa-driver wext
wpa-ssid "your ssid"
wpa-psk all hex here
wpa-proto WPA
wpa-key-mgmt WPA-PSK

References:
http://wiki.debian.org/WiFi
http://wiki.debian.org/WiFi/HowToUse
/usr/share/doc/wpasupplicant/README.Debian.gz (use mc or gunzip this)
http://wiki.debian.org/WiFi/HowToUse
manuals: interfaces