Sometimes the error message "Service Unavailable" shows on the home page instead of the main page of the site. The error logs show that the application is restarting and that some of the tables can't be found to drop and recreate.
Here is one of the errors:
THREAD ID: 1
TYPE: DataSprings.DNN.Modules.DynamicUserDirectory.DUDSchedulerClient
EXCEPTION: Cannot drop the table 'dbo.tempDUDProfile', because it does not exist or you do not have permission. Cannot drop the table 'dbo.tempDUDPivot', because it does not exist or you do not have permission. There is already an object named 'tempDUDProfile' in the database.
RESCHEDULED FOR: 3/21/2010 1:17:51 AM
SOURCE: STARTED_FROM_BEGIN_REQUEST
ACTIVE THREADS: 1
FREE THREADS: 0
READER TIMEOUTS: 0
WRITER TIMEOUTS: 0
IN PROGRESS: 0
IN QUEUE: 9
Server Name: CLE02WEB08