I've been cursing the wireless card in my computer since I pieced it together last week. It's an Asus PCE-N13. It didn't require any extra driver installation under either Windows 7 x64 or Ubuntu 10.10. However, the signal was very poor in Windows, with constant drop-outs, and it would not detect any networks at all in Ubuntu.
I haven't found a solution to Windows problems yet, but I blacklisted a few modules in Ubuntu, namely by adding these lines in /etc/modprobe.d/blacklist.conf:
Now Ubuntu is connecting like a champ. Blazing fast, and reliable. It seems to be using the rt 2860sta driver instead of the blacklisted ones now.
I originally found this information on the Ubuntu forums: http://www.uluga.ubuntuforums.org/showthread.php?t=1579053&page=2