Please follow following steps blindly to get wireless working on ubuntu machine.
Here are the steps…
On a fresh clean Ubuntu machine:
1. Disable the “Support for Atheros 802.11 wireless LAN cards” on Hardware Drivers, and reboot your box.
2. In a terminal:
2.1 Updates all package lists
# sudo apt-get update
2.2 Update driver.
# sudo apt-get install linux-backports-modules-intrepid-generic
Thanks to Gautam, directing me correct way 🙂