从 PPA 更新 network-manager（PPA 为开发源），步骤为：
1. sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys BC8EBFE8
2. 在/etc/apt/sources.list最后加上
deb http://ppa.launchpad.net/network-manager/trunk/ubuntu karmic main
deb-src http://ppa.launchpad.net/network-manager/trunk/ubuntu karmic main
3. sudo aptitude update
4. sudo aptitude safe-upgrade