If you are working with Sql Server Management Studio 2008 and trying to manage a database on a hosted server, you probably have run into this error when opening the Databases node in Object Explorer.
Error 916 - Server principal "userx" is not able to access the db "dbwhatever" under current security context
Searching around we see it's a known issue but no real workaround. The only clue I had of what was going on was that the reason this was happening was because of the Object Explorer Details view of the databases which gives a ton of information on each database. Unfortunately, in a shared environment, you don't have permissions to gather this data from most databases. The error isn't handled cleanly and I think it has something to do with a setting for the Auto_Shutdown...but regardless, the bug exists and seemingly no fix for us using shared servers.
However, I've found a workaround!! After the error comes up, click ok through the error. You will still get access to the system tables. This allows you to click on the Databases node to bring up the Object Explorer Details screen. From there you can right-click on the header to change the viewable columns. Deselect everything except for the name field. Refresh the view and all the tables will come up. In a shared environment, I could care less about just about everything but the name, so I'm not really losing anything.
Problem solved, error worked around and we don't have to wait on and hope that MS does something about the error.