Login Problem Active DIrectory Bound Macs 10.6.1

This problem is only appearing intermittently. Users are unable to login to certain machines, others with the same image work fine. I tracked down this error in the /Library/Logs/DirectoryService/DirectoryService.error.log log, which looks like the problem but I don't know what it means. I have no idea what it means and am wondering if anyone knows what the cause may be. 2009-10-13 20:33:37 EDT - T[0x0000000101D4E000] - User 'user.name' (/Local/Default) - ID XXXXXX 2009-10-13 20:33:37 EDT - T[0x0000000101D4E000] - User 'user.name' (/Active Directory/domain.edu) - ID XXXXXX 2009-10-13 20:33:37 EDT - T[0x0000000100381000] - Misconfiguration detected in hash 'Kerberos':