Problems with kerberos and forest domain

Hi,

I have a simple Apache setup that works fine when I create a keytab on a domain level authentication works fine. When I create a keytab at the forest level authentication does not work. I get the following error message. Does anyone know what I am doing wrong here? I validated there is the SPN is unique on the AD side.

[Wed Nov 13 10:55:49 2013] [debug] src/mod_auth_kerb.c(1707): [client x] Client didn't delegate us their credential
[Wed Nov 13 10:55:49 2013] [debug] src/mod_auth_kerb.c(1735): [client x] Warning: received token seems to be NTLM, which isn't supported by the Kerberos module. Check your IE configuration.