Sp_MSForEachDB As A Weird Behaviour

I am using SQLExpress for Unit Testing my application. In the Unit Tests, I use a local database file that is attached automatically in SQLExpress when the Unit Test uses it.

FYI, in the Unit Test I use the following connection string :


"Data Source=.SQLEXPRESS;AttachDbFilename=|DataDirectory|MyUnitTestDatabase.mdf;Integrated Security=True;User Instance=False;Pooling=false"

By accident, the MyUnitTestDatabase.mdf file was marked as ReadOnly. So, after executing several times the unit Test, the attached databases appear in grey in the SQL Server Management Studio Express. That's normal ! The problem I want to report here occurs when I execute the following script in SQL Server Management Studio Express:


use master
go
sp_MSForEachDB 'Print ''?'''
go

In .SQLExpress, I currently have 8 databases (The three last databases are those attached by the unit tests. They are ReadOnly):


- master
- model
- msdb
- tempdb
- MyUnitTestDatabase (the original db copied and used by the Unit Tests. It's not ReadOnly)
- 1E6AA4A60F3733D37F016842D4626B8B_X34058MYSERVICETESTRESULTSX34058_N17400 2008-03-12 17_22_03OUTMYUNITTESTDATABASE.MDF
- ADA9F382DFBC95C8334EF95336C98274_X34058MYSERVICETESTRESULTSX34058_N17400 2008-03-12 17_13_57OUTMYUNITTESTDATABASE.MDF
- F00BF38C8BB8F07D37FCC4E918CF815E_X34058MYSERVICETESTRESULTSX34058_N17400 2008-03-12 17_10_04OUTMYUNITTESTDATABASE.MDF

When executed, the script mentioned above displays sometimes all the databases and sometimes only the 4 first databases ?!?!

I did a demo to various colleagues here, pressing F5 many times in the Script windows. It's seems taht it displays 4 names or 8 names "at random"... (I always wait for the message "Query executed successfully" before pressing again F5).

I have to understand the problem here because I use sp_MSForEachDB to detach all the databases at the end of the Unit Tests and it also fails from time to time...

Thx in advance for any tip that could help me in finding the origin of this problem

V.

PS. : FYI, here is the stored proc I use to automatically detach the databases at the end of the unit tests


declare @spid int
declare @killstatement nvarchar(10)
IF @database like '%TESTRESULTS%'
BEGIN


-- Declare a cursor to select the users connected to the specified database
declare c1 cursor for select request_session_id
from sys.dm_tran_locks
where resource_type='DATABASE' AND DB_NAME(resource_database_id) = @database
open c1
fetch next from c1 into @spid
while @@FETCH_STATUS = 0
begin

-- Don't kill the connection of the user executing this statement
IF @@SPID <> @spid
begin

-- Construct dynamic sql to kill spid
set @killstatement = 'KILL ' + cast(@spid as varchar(3))
exec sp_executesql @killstatement
end
fetch next from c1 into @spid
end
close c1
deallocate c1

exec msdb.dbo.sp_delete_database_backuphistory @database
exec master.dbo.sp_detach_db @database, 'true'
END
END

Possibly I was not detaching the databases in a "clean way" and my system databases are now corrupted ? Is such a case, what should I do in addition to the code here above to correctly detach the databases ?