Data Import and Export Wizard Error.

I use SQLNameSapce to load SqlServer2000's Data Import and Export Wizard in VB.NET. The Wizard is running normally,but when I click the next button,Nothing Happened.
The CODE
......
Dim lvODatabase As SQLNS.SQLNamespaceObject = Me.mvSQLNs.GetSQLNamespaceObject(lvHDatabase
If lvODatabase Is Nothing Then Exit Su

lvODatabase.ExecuteCommandByID(SQLNS.SQLNSCommandI D.SQLNS_CmdID_DTS_EXPORT, Me.Handle.ToInt32, SQLNS.SQLNSModality.SQLNamespace_PreferModal
......

If I us
"lvODatabase.ExecuteCommandByID(SQLNS.SQLNSCommand ID.SQLNS_CmdID_DATABASE_BACKUP, Me.Handle.ToInt32, SQLNS.SQLNSModality.SQLNamespace_PreferModal)
instead o
"lvODatabase.ExecuteCommandByID(SQLNS.SQLNSCommand ID.SQLNS_CmdID_DTS_EXPORT, Me.Handle.ToInt32, SQLNS.SQLNSModality.SQLNamespace_PreferModal)

Database Backup Wizard run normally
Why? anyone can help me