Once again, I can't understand your problem clearly. The code does not create any problem with any mouse event including the MouseDown and MouseUp events. I receive these events properly in the user control class.
Add the following lines to the user control code window along with the above code and see the response in the debug window when you click on the user control.
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[tt]
Private Sub UserControl_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)
Debug.Print "MouseDown", Button, Shift, X, Y
End Sub
Private Sub UserControl_MouseUp(Button As Integer, Shift As Integer, X As Single, Y As Single)
Debug.Print "MouseUp", Button, Shift, X, Y
End Sub[/tt]
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If you want to raise these events in the external interface of the user control available to the container of the control (i.e. the form) then you have to declare these events and raise them from your user control's code, when you receive these events in your the user control class (like the normal practice.)
Hope this makes some sense.