Question Transport-level Error

Hi all,

I'm having a little problem with my sqlserver 2005.

I'm trying to crate a user in Microsoft SQL Server Management Studio throug a query.

Like this:
-------------------------------------------------------------------------------------------
USE [master]
GO
CREATE LOGIN [MYUSER] WITH PASSWORD=N'MYPASSWORD', DEFAULT_DATABASE=[MYDB],
DEFAULT_LANGUAGE=[us_english], CHECK_EXPIRATION=OFF, CHECK_POLICY=OFF
GO
ALTER LOGIN [MYUSER] ENABLE
GO

USE [msdb]
GO
CREATE USER [MYUSER] FOR LOGIN [MYUSER];
GO
GRANT EXECUTE ON [sp_start_job] TO [MYUSER]
GO
EXEC sp_addrolemember 'db_datareader', 'MYUSER'
GO
EXEC sp_addrolemember 'db_datawriter', 'MYUSER'
GO
EXEC sp_addrolemember 'SQLAgentOperatorRole', 'MYUSER'
GO
EXEC sp_addrolemember 'SQLAgentUserRole', 'MYUSER'
GO
EXEC sp_addrolemember 'SQLAgentReaderRole', 'MYUSER'
GO

Use [MYDB]
GO
CREATE USER [MYUSER] FOR LOGIN [MYUSER]
GO
EXEC sp_addrolemember 'db_datareader', 'MYUSER'
GO
EXEC sp_addrolemember 'db_datawriter', 'MYUSER'
GO
------------------------------------------------------------------------------------------
And drops the user by executing following:

Use [MYDB]
GO
EXEC sp_dropuser 'MYUSER'
GO

USE [msdb]
GO
REVOKE EXECUTE ON [sp_start_job] TO [MYUSER]
GO
EXEC sp_droprolemember 'SQLAgentOperatorRole', 'MYUSER'
GO
EXEC sp_droprolemember 'SQLAgentUserRole', 'MYUSER'
GO
EXEC sp_droprolemember 'SQLAgentReaderRole', 'MYUSER'
GO
EXEC sp_dropuser 'MYUSER'
GO

USE [master]
IF EXISTS (SELECT * FROM sys.server_principals WHERE name = N'MYUSER')
DROP LOGIN [MYUSER]
------------------------------------------------------------------------------------------


-Then if I from a query, first creates the user, then drops the user, I can't create him again?? I get's the following error when trying:

Msg 10054, Level 20, State 0, Line 0
A transport-level error has occurred when sending the request to the server. (provider: TCP Provider, error: 0 - An existing connection was forcibly closed by the remote host.)

I'f i then runs the createscript again, the user is created correctly.

Is there a way to avoid this foced lockout? Or how do i "refreash" my connection, without dataloss?

Best Regards
Henrik