Can't add BarButton in Inherited Form

How can I add a BarButton to DockableToolbar in an inherited form?

In VS2003 editor, if I customize my toolbar and add a barbutton, then save the form, then open again, the new barbutton is vanished.

I did that:
- create Form1 with a barmanager1 and a dockable toolbar
- set the barmanager as "public"
- create Form2 and inherit from Form1
- open the editor: I can see barmanager1 and my toolbar
- add a BarButton: I can see the new barbutton
- clos & save Form2
- open Form2: no new barbutton (I have the Command, I don't have the CommandLink)

I'll send you a sample project.