workbookopen doesn't function

[P Westerman via OfficeKB.com]

As newbee, I read the MSExcel-helpfiles on the WorkbookOpen event and it
did work for a short while. Strange enough it stopped working and I can't
find out why.
This is what I did:

STEP1: I created an Eventclassmodule ("EventClassModule") with the
following code:

Public WithEvents App As Application
Private Sub App_WorkbookOpen(ByVal Wb As Workbook)
Run ("check_user")
End Sub

STEP2: I ran the InitializeApp procedure:

Sub InitializeApp()
Dim X As New EventClassModule
Set X.App = Application
End Sub

Does anybody know why the macro isn't run anymore?