Users can't Logon After Server Reboot

I currently have an Openfire Server running on a Windows Server 2008R2 box using PHP/IIS/MySQL. Users authenticate using LDAP. The system was up and running perfectly for 2 days. After the reboot no one can authenticate. This would include both from clients and the Admin panel.

I see the following error in info.log: - User Login Failed. PLAIN authentication failed for:********

This happened once before and I had to reinstall. I would really like to avoid that especially if it means I have to reconfigure the entire system again.

Thanks for reading.