are u sure you have the broadcom chipset? I have the same Laptop and my Chipset is the Intel 3945abg ....
How did you test managed mode?
My commands to connect an AP with WEP are:
Maybe your ap isn't running a dhcp server, so try to set the ip manually.Code:modprobe -r ipwraw && modprobe iwl3945 iwconfig wlan0 key yourkey dhclient wlan0
If nothing helps, it might be usefull to see your step by step commands for further help.