Citrix Anon/guest Logon Works On 2K3 Not On 2K8

[zmag]

We are cutting over from PS4 on W2k3 to XenApp 5 on W2k8. When we test our anon apps (exam, logon and some kiosks) they fail to properly authenticate to the 2008 server. Instead of allowing OS access it brings us to the logon screen.

Our config is as follows;
Thin client starts and grabs a dhcp reservation file, that points it to an ftp server and share. The ftp server has one share for each anon app.

\\ftpserver\ C:\Inetpub\ftproot\exam
\\ftpserver\ C:\Inetpub\ftproot\logon
\\ftpserver\ C:\Inetpub\ftproot\kiosk ect


Each of the shares has a wnos.ini that specifies the ica connection settings, this works fine in W2k3 but the same file fails in W2k8. Here is a wnos.ini to launch exam.

#Wyse Terminal signon settings
signon=0
autoload=1
Priviledge=None

#ICA Connection
connect=ica \
description="logon" \
icon=default \
username=guest \
password= \
domainname=company\
browserip=nil;192.168.40.111;192.168.40.113;192.168.40.115;192.168.40.117 \
application=logon \
autoconnect=1 \
Resolution=1024x768 \
Fullscreen=yes


At this point it seems that it is the OS (2008) that somehow must allow the guest user to pass, but I cant verify this.
Is there an option or setting to allow scripted anon logons access?

Thanks in advance.