Wireless on my Dell Latitude E5320 doesn't work on Ubuntu but works on Linux Mint. What can I do to make it work?

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http://unix.stackexchange.com – I have dualboot Ubuntu 12.10 & Linux Mint 14, both are clean install & updated with the latest. My wireless works flawlessly on Linux Mint but it's very unreliable on Ubuntu: every 15~20 minutes, the wireless icon still shows "connected" status but I can't go to any website. Pinging URL & IP both result in no network activities. Reboot fix the problem but it would happen again within 15~20 minutes. I really like Unity. Any idea to help make Ubuntu works for me? Or what's the different in wireless module between Linx Mint & Ubuntu? Anyway I can bring it from Linux Mint to Ubunt (HowTos)