I have a MS SQL 2005 Std. in a domain with two Windows Server 2008 Std. domain controllers. Logins for the SQL are defined by domain users / groups.
Last friday there was a planned reboot of both domain controllers (not the SQL), one after the other. Although DC02 has had some problems at that time, when i tried to open the snap-in I got an error "...The server is not operational". Anyway, after the reboot everything was fine on that DC. Yesterday (monday) several users (all within the same group) weren't able to write in the db they normally have full access to. Interestingly, one user that had a constant connection for the past two weeks (a tool that terminates doubles) didn't experience any problems. We then decided to reboot the SQL and everything was working.
Can it be that a temporary loss of connection to the DC results in a loss of permissions?