Workbook Automatically Opens When Opening/Closing Any Other

I have a problem, where every time I close or open any workbook, Excel prompts me to "Enable or Disable Macros" in one particular workbook, wether I have tried to open it or not. In the said workbook, I have a macro that automatically updates a pivot table upon selecting the worksheet where the pivot table resides.

The code for it is as follows:

Sub UpdateIt()
Dim iP As Integer
Application.DisplayAlerts = False
For iP = 1 To ActiveSheet.PivotTables.Count
ActiveSheet.PivotTables(iP).RefreshTable
Next
Application.DisplayAlerts = True
End Sub

Private Sub Worksheet_Activate()
Call UpdateIt
End Sub

There is something in the code that calls UpdateIt any time a workbook is opened, closed or selected.