Hello,
What version are you running?
Here are few Symantec Knowledgebase Articles, which may help you.
1) Best Practices guide for installing the SEPM 11 RU5 and later using SQL Server 2008 Database.
http://www.symantec.com/business/support/index?page=content&id=TECH96451
2) How to troubleshoot Symantec Endpoint Protection Manager SQL connectivity.
http://www.symantec.com/business/support/index?page=content&id=TECH95721
3) The Home, Monitors and Reports tabs in the Symantec Endpoint Protection Management console fail to load while attempting to connect to the database.
http://www.symantec.com/business/support/index?page=content&id=TECH102692