Userform Cancel Button _Intermittently_ Unresponsive?

Question

The attached VBA procedures are for a progress bar userform. Everything works as expected, except that the cancel button is intermittently unresponsive.

I say intermittently because, 95% of the time I have to click the cancel button numerous times before the procedure stops. I can see the button click event being animated, but the procedure isn't being interrupted. It looks as though something is stealing focus from the cancel button before the button down event can occur.

The escape and window close buttons respond as expected with one click.

What do I need to do to make the cancel button respond correctly? Thanks!

Update: I noticed that when I click and hold down on the cancel button, instead of the button staying "down" it gets kicked back up. So apparently something is resetting the button state to up, fast enough that the procedure is not catching the down state to fire the click event.

Here is the code in the userform module (named UserForm1):

Private mbooUserCancel As Boolean

Public Property Get UserCancel() As Boolean
    UserCancel = mbooUserCancel
End Property

Private Property Let UserCancel(ByVal booUserCancel As Boolean)
    mbooUserCancel = booUserCancel
End Property

Public Sub UpdateProgress(CountTotal As Long, CountProgress As Long)
    On Error GoTo Error_Handler
    ProgressBar1.Value = CountProgress / CountTotal * 100
    DoEvents
Error_Handler:
    If Err.Number = 18 Then CommandButton1_Click
End Sub

Private Sub CommandButton1_Click()
    Hide
    UserCancel = True
End Sub

Private Sub UserForm_QueryClose(Cancel As Integer, CloseMode As Integer)
    Cancel = True
    CommandButton1_Click
End Sub

Private Sub UserForm_Activate()
    With Application
        .Interactive = False
        .EnableCancelKey = xlErrorHandler
    End With
End Sub

Private Sub UserForm_Terminate()
    Application.Interactive = True
End Sub

Here is the code for the module (named Module1) that calls the UserForm1:

Sub TestProgress()

    On Error GoTo Error_Handler

    Dim objUserForm As New UserForm1
    Dim lngCounter As Long
    Dim lngSubCounter As Long

    With objUserForm
        .Show vbModeless
        DoEvents
        For lngCounter = 1 To 5
            If .UserCancel Then GoTo Exit_Sub
            For lngSubCounter = 1 To 100000000
            Next lngSubCounter
            .UpdateProgress 5, lngCounter
        Next lngCounter
        Application.Wait Now + TimeValue("0:00:02")
        .Hide
    End With

Exit_Sub:

    If objUserForm.UserCancel Then
        MsgBox "User Cancelled from UserForm1"
    End If
    Exit Sub

Error_Handler:

    If Err.Number = 18 Then
        Unload objUserForm
        MsgBox "User Cancelled from Module1"
    End If

End Sub

Answer 1

Works for me on the first click every time. Try unloading any add-ins or any other code that could be running inside the container app and see if that helps.

Answer 2

The answer is to use modal userforms for progress bars so that the button click event can fire without getting obscured by processing in the calling procedure.