can't establish connection with WEP security key

[Fahad]

Binary package hint: knetworkmanager

I am using Kubuntu 10.04 and I can't establish a wireless connection with WEP security method. I have installed ubuntu 10.04 in other machine and I can establish the connection without problem.

this is information form lshw -C network command:

       description: Wireless interface
       product: PRO/Wireless 5100 AGN [Shiloh] Network Connection
       vendor: Intel Corporation
       physical id: 0
       bus info: pci@0000:03:00.0
       logical name: wlan0
       version: 00
       serial: 00:26:c6:86:fa:0e
       width: 64 bits
       clock: 33MHz
       capabilities: bus_master cap_list ethernet physical wireless
       configuration: broadcast=yes driver=iwlagn latency=0 multicast=yes wireless=IEEE 802.11abgn
       resources: irq:31 memory:f4200000-f4201fff