I upgraded the wireless card from Atheros AR9285 to Atheros AR9287 which can do 300 Mbps connections. However, I found that the problems in wifi connection: dropped frequently (almost every 30 seconds or so) in Ubuntu. This problem did not occur in Windows 7. So I had a new task at hand: fix Atheros AR9287 wireless card problems in Ubuntu.
Googling led me to this post: http://ubuntuforums.org/showthread.php?t=1378485 and I began troubleshooting Wifi.
However, it was for Karmic/Jaunty and did not work for Lucid. In Lucid Lynx, install the following package to get the Atheros AR 9287 wireless card to work properly.
Fix for Atheros AR9287 Wireless Card Problems
sudo apt-get update sudo apt-get install linux-backports-modules-wireless-lucid-generic
Reboot your computer and hopefully your problem is gone like it did with mine. Alternatively, you could upgrade to on one of the cards listed below that have been tested to work with Ubuntu.
Good Wifi Cards that are compatible with Ubuntu
Update: If this solution posted on this page does not work for you in Ubuntu 12.04 LTS Precise Pangolin, please check this post.