Modifications in Windows 2k8 R2 that prevent krb5 referal in RODC setup?

[Joshua Hawkinson]

Hi guys,

I seem to have uncovered a defect in the latest stable version of samba (3.5.5) where I'm unable to authenticate through Kerberos to a 2008 R2 read only domain controller (RODC).  I've been digging in on this issue for about a couple of days and I've found that the problem only seems to occur during TGS-REQ to the RODC.  The RODC seems to reject this request (with error 31 decrypt integrity check failed) without forwarding it on to the writeable DC. If I replace the 2008 R2 RODC with a standard 2008 RODC the problem does not occur.  Also if I set the samba server to directly authenticate to the writeable DC no problems occur (obviously).  I've received word from an engineer at Microsoft that the problem is due to.... Well I'll paste in his message