WPA2 Enterprise connections don't work

Question

Hi everyone,
Configuration: MacBook Pro 7,1, 2,4GHz, Mac OS X 10.6.5.
Three user accounts (one for me, two for friend's backup), two of them have admin rights. I'm using one of these accounts.
I'm having a strange issue with *WPA2 Enterprise*-based access points, namely, the private one on my university's campus, and the eduroam one. Eduroam is, roughly, a SSID that is available in participating institutions worldwide, and allows connection from personnel registered in any of these institutions without having to ask for a guest access.
On eduroam, one is supposed to select the eduroam SSID in the list of network available, select "Security: WPA2 Enterprise", and type his institutional email address as a username. "Password" should remain blank for now, and in front of the "802.1X", select "Auto". On clicking the "Connect" button for the first time, a "Check certificate" dialog should appear with three buttons, "Display", "Cancel", "Continue", where one would click "Continue". Finally, a "802.1X authentication" dialog would appear, when a user would put his email address as username, and type in his institutional password to log in. Then, the user would be online without further fuss.
On my university network, it's even simpler. One should select it, type in the IT login, then the corresponding password, before being allowed to be online.
On my normal user account, I never get the "Check certificate" dialog for eduroam, an on the uni's network, it never seems to connect. Ultimately, I get the exclamation point over the wireless waves, meaning that the card self-assigned an IP. Then it tries to connect again (the icon is waving), then fails again. No other authentication is affected, and a quick look in the logs doesn't show anything salient.
On the other user account, the connection to either of these SSID works as written, on the first try.
So it's no hardware issue.
I first tried to create a new wireless profile, and recreate the connection. It failed, once again, for both networks.
So to the Genius Bar I went. Since it's a login issue, we deleted the ~/Library/Keychans/login.keychain item, rebooted. Since the issue couldn't be reproduced in store, he advised me to delete the "session" keychain and reboot if the problem persisted. He asked me if the computer crashed while I was logged in anywhere in the past (before 10.6.5), and yes I said, adding that I let AppleJack do the automated repair. He checked with a colleague, on a tech forum, spent 30 min with me, but came back with the dreaded conclusion that, at least in that store, they ended up doing what he named "partial restore" to correct a similar issue, in contrast to "archive and install".
Off to the uni I went, and recreating the connection failed again. In the Access Keychain, I then removed the session keychain, with both the references and files (default is reference only), since they referred to passwords I already knew, rebooted, logged in, and tried to connect, to no avail. The other user account still works.
What else should I try? Ironically enough, I reinstalled OS X more times in two years than I did Windows in eight, and want to avoid the time-consuming step of reinstalling applications, and the very tricky part - ownership issues - of manually importing documents and only selected settings.

Answer 1

I was chasing a similar authentication issue on OS X ≥ 10.5.8 for quite some weeks. My setup does use MS 2008 Server (AD, NPS, Radius) and SonicWall SonicPoint (multi SSID on VLAN).
When I started evaluating the different options, I didn't realize such issues But when it came to the final usage guidelines I had serious issue connecting with Mac OS X to the WPA2 Enterprise Network (BlackBerry and iOS was never an issue)!
I finally did work out, that you can only authenticate once successfully if you use the "Ask to join networks" popup - instead I had to select the network manually from the airport, provide my credentials and select "remember this network"to store the network and it's radius profile! I guess this behavior may have something to do with the credentials stored/reused in/from the keychain for the second login.
Also, I did notice you have to make sure you quit your system preferences each time you expect a change due to newly stored networks or radius profiles!
Hope this may help other users to troubleshoot similar issues!