BUG: Command events fired only to last addin loaded in Visual Studio .NET

When two addins set event handlers to the same command of the Visual Studio .NET IDE, only the last one loaded receives events from that command.

This seems a bug in the Visual Studio .NET IDE

Create two add-ins with the code (VB.NET) of below. Each add-in shows a message when each connected and each one should show a message when the user clicks the Help \ About menu. However, only the last loaded add-in shows the second message.
 
   Private m_objAddIn As AddIn
   Private WithEvents m_objAboutCommandEvents As EnvDTE.CommandEvents
 
   Public Sub OnConnection(ByVal application As Object, ByVal connectMode As Extensibility.ext_ConnectMode, _
      ByVal addInInst As Object, ByRef custom As System.Array) Implements Extensibility.IDTExtensibility2.OnConnection
 
      Dim objDTE As EnvDTE.DTE
      Dim objCommand As Command
 
      objDTE = CType(application, EnvDTE.DTE)
      m_objAddIn = CType(addInInst, EnvDTE.AddIn)
      objCommand = objDTE.Commands.Item("Help.About")
      m_objAboutCommandEvents = objDTE.Events.CommandEvents(objCommand.Guid, objCommand.ID)
 
      System.Windows.Forms.MessageBox.Show("Addin " & m_objAddIn.Name & " connected")
 
   End Sub
 
   Private Sub m_objAboutCommandEvents_BeforeExecute(ByVal Guid As String, ByVal ID As Integer, _
      ByVal CustomIn As Object, ByVal CustomOut As Object, ByRef CancelDefault As Boolean) _
      Handles m_objAboutCommandEvents.BeforeExecute
 
      System.Windows.Forms.MessageBox.Show("Before showing about window from addin " & m_objAddIn.Name)
 
   End Sub