I was more thinking about the rights in the security tab.
I logged in with my windows auth and created a new user under Security -> Logins
if you right click at a user and view the properties you can select a few pages. Click on User Mapping. At that page you select the map column for the 3 databases (account, shard, log) and I gave that user for every database the db_owner membership.
so this way I never had any problems with select problems or update problems ect. so You might want to check these things out