LCS 2003: Windows Messenger on XP clients signed out overnight using Kerberoshttp://blogs.technet.com/toml/archive/2004/12/21/328725.aspxThere is a known issue with LCS 2003 and Windows Messenger being signed out overnight. The root cause is a known issue with fix for Kerberos. The KB article is still being published so not everyone knows about the issue. You will want to enable the clienten-USCommunityServer 2.1 SP1 (Build: 61025.2)