I've had this problem too.
Here's a workaround: http://www.ubuntugeek.com/how-to-fix-network-manager-disabled-problem-in-ubuntu-10-04-lucid.html
I've had this problem too.
Here's a workaround: http:// www.ubuntugeek. com/how- to-fix- network- manager- disabled- problem- in-ubuntu- 10-04-lucid. html