Stop workbook from running 'cancelled' Timed code - vba

Question

Edit: I've managed to solve the problem below by using Application.EnableEvents = False in Workbook A to stop the Workbook_Open() code from running in Workbook B but am still stumped by the problem if anybody care to explain?
I've got Workbook A opening, editing, saving and closing Workbook B. As Workbook B is used by multiple users, I made it switch to Read-Only mode upon opening and display a pop-up message. However, when running the code from Workbook A, I want to stop the message box from opening. I used Application.OnTime to change Workbook B to Read-Only upon opening and to cancel the pending code upon saving within 10 seconds.
Problem: The code works when I open Workbook B directly and save within 10 seconds but when running a code from Workbook A to open=>edit=>save=>close Workbook B, Workbook B will open by itself even after it is closed.
After doing much research and trial and error by trying to use Public variables and Referencing VBA project, I settled on Application.OnTime using the resource below:
http://www.cpearson.com/excel/OnTime.aspx
Below is a sample of my code.
Private Sub Workbook_BeforeSave(ByVal SaveAsUI As Boolean, Cancel As Boolean)
Call StopTimer
End Sub
Private Sub Workbook_Open()
Call StartTimer
End Sub
Public RunWhen As Double
Public Const cRunWhat = "Change_File_Access"
Public Const cRunIntervalSeconds = 15
Public DatabaseWB As Workbook
Sub StartTimer()
RunWhen = Now + TimeSerial(0, 0, cRunIntervalSeconds)
Application.OnTime EarliestTime:=RunWhen, Procedure:=cRunWhat, _
Schedule:=True
End Sub
Sub StopTimer()
MsgBox RunWhen
On Error Resume Next
Application.OnTime EarliestTime:=RunWhen, Procedure:=cRunWhat, _
Schedule:=False
End Sub
Sub Change_File_Access()
If Not Workbooks("WorkbookB.xlsm").ReadOnly Then Workbooks("WorkbookB.xlsm").ChangeFileAccess xlReadOnly
MsgBox "This file is set as Read-Only"
End Sub

Answer 1

Some quick testing shows the timer seems to be running within the context of the Workbook that the macro resides in - not the Workbook that you executed it from. So, you need to do one of 2 things - either quit the Excel application completely (probably not convenient) or reset the timer from the Worksheet you're running the code from.
I.e., in WorkbookA:
Dim book As Workbook
Set book = Workbooks.Open("WorkbookB.xlsm")
book.Save
Application.Run book.Name & "!StopTimer"
book.Close