Using Backtrack 5 R3, I tried connecting to my home wireless network. It's encrypted with a 64 bits WEP key (hexadecimal) - yes I know it's not very safe - but I can't get an IP address.
I made sure to select the right type of WEP Encryption, and that my key was correct.
At first I tried setting a static IP, but then the error was "unable to contact wireless access point".
Then I tried connecting via the command line using iwconfig and dhclient. Still no success.
Then I tried downloading and installing the latest drivers (stable and experimental - I tried both) from Linux Wireless for my network card, but I still get the same results.
Then I tried removing WICD and installing Network Manager for KDE instead; still no IP address.
Finally I switched back to wicd and did a "dpkg-reconfigure wicd", but it didn't change anything.
The laptop is an Acer Aspire 6530-5959, the wireless network chipset is Atheros 9000 series, and my router is a NETGEAR WNR100v2.
Connecting to the same network on the same computer worked fine in backtrack 3 and 4. This is definitely new.
Additional additional info:
Kali Linux works perfectly! It's awesome!