MDI Minimize to tray issue

 

When I try to minimize a ribbon by clicking the the close button on the parent form it automatically closes the subforms for some reason.

 

The unload code on the parent is:

Public Sub MDIForm_Unload(Cancel As Integer)
On Error Resume Next

Dim sMainCloseButtonFunction As Integer
    sMainCloseButtonFunction = ReadINIFile(App.Path & "\Preferences.ini", "Settings", "MainCloseButtonFunction", "")

    If sMainCloseButtonFunction = 1 Then
        Cancel = True

        Call MinimizeToTray
        Exit Sub
    Else
        mWidth = Me.Width
        mHeight = Me.Height
        SaveSetting App.Title, "Settings", "Width", mWidth
        SaveSetting App.Title, "Settings", "Height", mHeight

        Call SetWindowLong(Me.hwnd, GWL_WNDPROC, OldWindowProc) 'unload resize form

        Unload Me: End
    End If
End Sub

 

The minimze code:

Public Sub MinimizeToTray()
    If Not Minimized Then
        TI.MinimizeToTray Me.hwnd
        Minimized = True
        CommandBars.RecalcLayout
    Else
        TI.MaximizeFromTray Me.hwnd
        Minimized = False
        CommandBars.RecalcLayout
    End If
End Sub

 

And when I call the MinimizeToTray function via a Button it works fine.

Is this a bug or am I missing a piece of code or?