OP-manager application stops monitoring every day

Hi,

I have Op-manager installed with the DB inside an MS SQL 2005. The application server is a windows 2003. Almost every day the application stops monitoring the devices without any specific reason. There are no Down Time Schedules setup. When i try to login to the web page most of the times bu not always i get an error about the user table in the DB. In the same time the service is running fine. After the restart of the entire server all devices appeared as not monitored for a time.

What are the needed logs that can help you identify what could be the problem. It is important as I monitor with this tool 30 routers, 50 switches and more than 100 servers.

Thanks and Regards,
Razvan Despa