How to assign db_owner role to "sde" user

[RobertHu]

ArcSDE 9.3.1
SQL Server 2008 (SP1)

This is more a DBMS problem.

I built a SQL Server 2008 geodatabase using in SDE schema. Now I tried to grant the sde user the db_owner role for preparing the geodatabase upgrade (9.3.1 to 10). It failed with error message as,

Add member failed for DatabaseRole 'db_owner'. (Microsoft.SqlServer.Smo)
Additional information:
    An exception occurred while executing a Transact-SQL statement or batch.
    (Microsoft.SqlServer.ConnectionInfo)

        Lock request time out period exceeded.
        Lock request time out period exceeded. (Microsoft SQL Server, Error:1222)

I used the SA user to connect the instance in SSMS, and the SA is a member of sysadmin server role as well as a member of db_owner DB role.

Does anyone have same experience and have a solution?

Thanks!

[RobertHu]

An ESRI tech support analyst reproduced the behavior I had encountered on their site. He figured out a solution. It is that before grant sde user db_owner database role, STOP THE SDE SERVICE FIRST.

Good to know this. Thanks!