Help, Why the links not spread for GoBoxNode

By the way, What I need should just for 1 goboxport in the node.

the code for my node:
Namespace Node_Link_Demo
Public Class InfoNode2
Inherits GoBoxNode
Public Sub New()
Me.PortBorderMargin = New SizeF(1, 1)
Me.LinkPointsSpread = True
Me.Port.IsValidDuplicateLinks = True
Me.Size = New Size(50, 50)
Me.Resizable = True
Me.AutoRescales = False
End Sub
the links is overlaped from same link point:
What I need for my application should keep the links spread correcttly always like following :
Walter and Jake, Could you please give me any ideas ?