cannot be executed within a transaction

Hej,

Jeg har lavet det her fine script til at oprette Read only brugere på alle databaser på en server. Men på to ud af 12 server får jeg fejlen:

Msg 15002, Level 16, State 1, Procedure sp_addrolemember, Line 16
The procedure 'sys.sp_addrolemember' cannot be executed within a transaction.

Er der en setting på de to servere som gør denne forskel:

CREATE TABLE #USERS (username VARCHAR(10),userpassword VARCHAR(10))
GO
INSERT INTO #USERS (username,userpassword) VALUES ('RO_dsj','12345')
GO
--TILFØJ EN RÆKKE PER PERSON
--INSERT INTO #USERS (username,userpassword) VALUES ('BRUGERNAVN','PASSWORD')

DECLARE
@user VARCHAR(10),
@password VARCHAR(10),
@db VARCHAR(50),
@script VARCHAR(max)
set @script = ''

BEGIN tran
DECLARE usercursor CURSOR FOR
SELECT username,userpassword FROM #USERS

OPEN usercursor

FETCH NEXT FROM usercursor INTO @user,@password
WHILE (@@FETCH_STATUS = 0)
BEGIN

set @script = 'USE MASTER'+CHAR(10)+CHAR(13)
set @script = @script+'IF NOT EXISTS (SELECT 1 FROM sys.syslogins WHERE loginname ='''+@user+''')'+CHAR(10)+CHAR(13)
set @script = @script+'BEGIN'+CHAR(10)+CHAR(13)
set @script = @script+'CREATE LOGIN ['+@user+'] WITH PASSWORD=N'''+@password+''' ,DEFAULT_DATABASE=[master], CHECK_POLICY=OFF'+CHAR(10)+CHAR(13)
set @script = @script+'END'+CHAR(10)+CHAR(13)

EXEC(@script)

DECLARE dbcursor CURSOR FOR
SELECT name FROM sys.databases
WHERE name NOT in ('master','model','msdb','tempdb')

OPEN dbcursor
FETCH NEXT FROM dbcursor INTO @db
WHILE (@@FETCH_STATUS = 0)
BEGIN

set @script = 'USE '+@db+CHAR(10)+CHAR(13)
set @script = @script+'IF NOT EXISTS (SELECT 1 FROM sys.sysusers WHERE name ='''+@user+''')'+CHAR(10)+CHAR(13)
set @script = @script+'BEGIN'+CHAR(10)+CHAR(13)
set @script = @script+ 'CREATE USER ['+@user+'] FOR LOGIN ['+@user+'] WITH DEFAULT_SCHEMA=[dbo]'+CHAR(10)+CHAR(13)
set @script = @script+'END'+CHAR(10)+CHAR(13)
set @script = @script+ 'Exec sp_addrolemember N''db_datareader'', '''+@user+''''+CHAR(10)+CHAR(13)
set @script = @script+ 'GRANT CONNECT TO ['+@user+']'+CHAR(10)+CHAR(13)
set @script = @script+ 'GRANT VIEW DEFINITION TO  ['+@user+']'+CHAR(10)+CHAR(13)
--PRINT @script
EXEC(@script)

    FETCH NEXT FROM dbcursor INTO @db
END
CLOSE dbcursor
DEALLOCATE dbcursor

    FETCH NEXT FROM usercursor INTO @user,@password
END
GO

CLOSE usercursor;
GO
DEALLOCATE usercursor;
GO

commit tran

DROP TABLE #USERS
GO