Page_Load is firing twice in ASP.NET page

Just ran into this problem, and thought I would post an answer summarizing what I found, plus my actual issue.

1. img tags with src="" or Image tags with ImageUrl=""
2. Using AutoEventWireup="true" and adding a page handler
3. Having manually added the event handler (more common for C# than VB)
4. Handling both MyBase.Load and Me.Load
5. Variation on the missing img src, body { background-image: url(); }
6. Rewrite rule and missing favicon.ico 

and finally my issue….

My page inherited from a class that included a Page Load handler, which inherited from a class with a Page Load Handler.

Public Class C1
    Inherits System.Web.UI.Page
   Protected Overridable Sub PageLoad(ByVal sender As Object, 
                               ByVal e As System.EventArgs) Handles Me.Load
   End Sub
End Class

Public Class C2
    Inherits C1
    Protected Overrides Sub PageLoad(ByVal sender As Object, 
                      ByVal e As System.EventArgs) Handles Me.Load
        MyBase.PageLoad(sender, e)
    End Sub
End Class

Public Class MyPage 
    Inherits C2
    Protected Overrides Sub PageLoad(ByVal sender As Object, 
                      ByVal e As System.EventArgs) 
        MyBase.PageLoad(sender, e)
    End Sub
End Class

I tested this, and if you put a Handles on the method in MyPage, it will get hit 3 times…