Problemas para conectar con red wi-fi

[luis miguel <luisdiazr@gmail.com>]

Hola lista, instale mi tarjeta wifi con nsdiswrapper, lo instala
correctamente y detecta mi tarjeta correctamente pero no me puedo
conectar, ya he intentado varios metodos pero nada, tengo encriptacion
wep a 64 bits, no se cual sea el problema les añado los resultados de
ndiswrapper -l y mi archivo de /etc/network interfaces

debian:/home/luis# ndiswrapper -l
Installed ndis drivers:
netr8180                driver present, hardware present


# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet dhcp

auto wlan0
iface wlan0 inet dhcp
wireless-essid zahrup zagreb
wireless-key 16x21xx0dc


le añado tambien lo el resultado de ifup wlan0

debian:/home/luis# ifup wlan0
Internet Software Consortium DHCP Client 2.0pl5
Copyright 1995, 1996, 1997, 1998, 1999 The Internet Software Consortium.
All rights reserved.

Please contribute if you find this software useful.
For info, please visit http://www.isc.org/dhcp-contrib.html

sit0: unknown hardware address type 776
eth1: unknown hardware address type 24
sit0: unknown hardware address type 776
eth1: unknown hardware address type 24
Listening on LPF/wlan0/00:40:f4:ba:04:45
Sending on   LPF/wlan0/00:40:f4:ba:04:45
Sending on   Socket/fallback/fallback-net
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 4
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 5
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 14
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 9
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 12
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 16
No DHCPOFFERS received.
No working leases in persistent database.

Exiting.

Failed to bring up wlan0.



Les agradeceria sus sugerencias...
Gracias.