Solidworks 2015 SP5

Adding a derived configuration to a non active configuration seems to make the AddItemNotify fail on Assemblies.

My Test Code:

Function AssemblyDoc_AddItemNotify(ByVal EntityType As Integer, ByVal itemName As String) As Integer
     If EntityType = swNotifyEntityType_e.swNotifyConfiguration Or swNotifyEntityType_e.swNotifyDerivedConfiguration Then
          MsgBox("New Config Added")
     End If
End Function

Has anyone experienced this issue?