Rebooting Exchange 2011 causes errors and clients unable to connect automatically

We are currently running an Exchange 2010 server. We are considering moving our 2003 box users to 2010 and we also run Office Communicator. Recently, we rebooted our exchange 2010 server and since then, we have been running into errors. Our outlook clients are now unable to connect automatically as they are being asked for their passwords and they have to enter the correct passwords to connect. Unlike before, they can get connected automatically. I have set up my outlook in a way as to connect using my local area network. Problem is that Outlook is not activated anywhere and I don’t know where to start looking. Any idea that might help me is welcome.
