Vista SP1 + Kerberos problem

[<stenis@kth.se>]

Our Active Directory have a trust to KTH.SE which is running Heimdal Kerberos
0.7.2. We propagate KTH.SE accounts to our Active Directory where we then map
the accounts to use KTH.SE for authenticating. This has been working very well
with Vista so far but now that I started to test Service Pack 1 there is
something breaking as I can no longer access network shares and although I have
full rights and is the owner of the share Windows Vista presents a login prompt
which does not accept my credentials. Note that logging into the computer
itself works without problems but the problem lies when accessing a share. 

When trying to access the share I can see several failures in the event viewer
correlated to cifs along with the failure code Failure Code 0x3C on the server
side. I am troubleshooting this with Microsoft but maybe someone here can be of
assistance or possible even know what the problem is? 

Thanks!

Andreas Stenhall, KTH