Cannot login to GMS after upgrade to 2.0

I upgraded from version 1.2 to 2.0 on Sunday. Everything worked fine and mail flowed after the upgrade. I also changed the authentication method from LDAP to GroupWise per the recommendation in Danita's book. Everything appeared fine. I restarted the service. We had no problems on Monday but today, Tuesday morning, we are unable to connect to the server INCLUDING admin access to the Admin Web Console. I get the "Invalid user name/password" error. I have restarted GMS again and all services are running but still cannot access the console.
I would appreciate any help. Thanks,