hi Lycan,
I've thrown in my DGL-4300 for a bit, to see if it did the same thing. I forgot to check with it running 1.8 FW, but sure enough, it does it with 1.9 FW, and 2200BG. I don't have time to test, but it still gets stuck at the authenticating part, and then disconnects.
Still using the same encryption and all... WPA2-Personal. AES-CCMP as well.
This is also using the latest Intel drivers 12.0.4.0.
Hope this helps!
Thanks!
Edit: I haven't tried to force it using the WPA, or even TKIP, but I'm sure it won't work unless encryption is off.