Wep network - dell inspiron 6000

[linuxnoob0075]

I have a dell Inspiron 6000 and recently installed ubuntu 8.04. Im trying to connect to my wireless network which has a 128-bit ASCII encryption key and is open system, but when i try to connect with these settings it tries to connect and then pops up with the password dialog box once more. Does anyone know if there is something wrong with my configuration and/or what I should do?

Thanks