A curious thing, is there a reason that you can't declare sender as a specific type? For instance, if you had a number of textboxes and you wanted each one to select all it's text when you click on it could you use :
Public Sub TextBox_Click(ByVal sender As TextBox, ByVal e As System.EventArgs)
and add it as the Click Event handler to each textbox.
It seems kind of obvious to me, and it does work. But I'm wondering if there is something deep inside visual studio that'll get screwed up.