Your guide is great. 1 problem I encountered (which took 2hours to figure out) is that you have to specify the username as user@ and leave domain field blank in XP. Both in Windows Managed and Intel Pro wireless management software.
Step 1 of 2 : PEAP User
Confirm Password: xxxxxxxx
I found that entering entering localdomain in Domain: does not work. Just a heads up for others out there