wpa_supplicant wpa peap gtc connection - gtc failing?

[Da Rock]

I'm trying to access a uni network using wpa-peap with GTC 
authentication, and no matter what I've tried it fails.

I've come across the same error in most of my logs: "phase2 request: NAK 
type 6".

I've been at this for sometime, so I decided to contact the ICT who look 
after the radius servers, and they can't understand the why of the issue 
either- everything they can see ticks the right boxes, until my system 
says no to type 6.

Anyone know of the problem?

My network block looks like this in config:

network={
         #: <Network>
         ssid="<network ssid>"
         #+ any_bssid
         key_mgmt=WPA-EAP
         eap=PEAP
         identity="<network username>"
         password="<password>"
         phase1="peapver=0"
         phase2="autheap=GTC"
         ca_cert="<radius certificate>"
}

I have tried all combinations of peap_outer_success, peapver, peaplabel, 
but none work. I was informed the peapver should be 0 and thats about it.

Any pointers would be much appreciated.

Cheers