OK , try something else to get the source of error (your app , external app ..)
It's better your create a function that trap any error and returns a discriptive msgs.
VB Code:
  1. Try
  2.             Dim frm As Form1
  3.             frm.Name = "error"
  4.         Catch x As Exception
  5.             MsgBox(x.Source)
  6.         End Try