Funny with BackGroundWorker

I'm using the code below to delegate a database restore to a
BackgroundWorker component.  My problem is that the second time I execute
the restore, the private method RestoreDatabase is invoked twice.  The click
event of the button isn't being invoked twice, so it's somewhere else.  Any
suggestions?





        private void SetupDatabase()

        {

            buttonDatabaseSetup.Enabled = false;

            CurrentActionStatusLabel.Text = string.Format("Restoring
database {0}", WORKING_DATABASE);

            DataToolBackgroundWorker.DoWork +=
DataToolBackgroundWorker_DoWork;

            DataToolBackgroundWorker.RunWorkerAsync(new
MethodInvoker(RestoreDatabase));

        }



        void dt_ProgressChangeEvent(double percentComplete)

        {

            DataToolBackgroundWorker.ReportProgress((int)percentComplete);

        }



        void DataToolBackgroundWorker_DoWork(object sender, DoWorkEventArgs
e)

        {

            MethodInvoker m = e.Argument as MethodInvoker;

            m.Invoke();

        }



        private void RestoreDatabase()

        {

            DataTool dt = new DataTool();

            dt.ProgressChangeEvent += dt_ProgressChangeEvent;

            dt.RestoreDatabase(Properties.Settings.Default.DevDBBackupPath,
WORKING_DATABASE);

        }