Asp.net - Button Control Not Firing

In the page load, I wanted to know what button created a postback on the page load. Through research I have found this snippet below and it works as expected. So here is my scenario of events that occur when click on the button.

1. Click the button does a postback
2. Runs the function below and tell me the id of the button
3. Runs the clicked event handlers for that button

Protected Sub btnCalc_Click(ByVal sender As Object, ByVal e As EventArgs) Handles btnCalc.Click
' Do this
End Sub

The problem comes in when I click the second button, it does steps 1 and 2 but NEVER DOES 3. Through testing, I have that it only does 1, 2, and 3 on the first button clicked.

Function GetPostBackControlName() As String
Dim control As Control = Nothing
Dim ctrlname As String = Page.Request.Params("__EVENTTARGET")

[Code]....