After installing Lucid Lynx Ubuntu 10.04 on my laptop, I had no wireless. The wireless worked find under the previous two versions of Ubuntu. The solution is to install the Broadcom 802.11 Linux STA wireless driver source.
$ sudo apt-get install bcmwl-kernel-source $ sudo reboot
After rebooting, wireless works.
Updated: BTW my laptop is an HP Compaq nx6325.
Here are the vendor and device codes for my wireless.
$ sudo lspci -nn 30:00.0 Network controller : Broadcom Corporation BCM4312 802.11a/b/g [14e4:4312] (rev 01)