You can get a direct replacement for the IPN2220, Acer part #ki-cax01-005 is based on the Intel IP2200.
You can buy one at
http://www.impactcomputers.com/ki-cax01-005.html
for 59.95.
I installed mine in about 4 minutes and it works flawlessly. The activate/deactivate button works and has Vista drivers on the Intel website.
Tim
EggHeadCafe - .NET Developer Portal of Choice
http://www.eggheadcafe.com