This is basically just a repost of the same issue I had when Karmic Koala launched
Ubuntu 10.4 (Lucid Lynx) launched today and I figured it was time to do an install from scratch onto my Dell D830 Latitude laptop. Everything went quite smoothly but when it started up I noticed two issues:
Problem 1: No wireless
I know the Broadcom card inside the laptop isn’t the greatest, but the last two Ubuntu releases it has worked out of the box. The following command enabled the card after a reboot:
sudo apt-get install bcmwl-kernel-source
Problem 2: Really slow DNS lookups (because of IPV6)
As documented on Launchpad, there still doesn’t seem to be an official fix. Strangely disabling IPV6 in /etc/sysctl.conf didn’t solve anything, however disabling it in Firefox at least fixes the issue in the browser. Just type about:config in the address bar, and set network.dns.disableIPv6 to false.