VBA function in ControlsSource wont fire

Question

On an continuous form i have an checkbox with controlsource = "=hasDocument([Nr])" the function is defined in the form as following:

Private Function hasDocument(Nr As Variant) As Boolean
    On Error Resume Next

    If IsNull(Nr) Then
        ' pass
    ElseIf err <> 0 Then
        ' pass
    Else
        hasDocument = DExists("ID", "Kurztexte", "Aufwendungs_Nr=" & Nr)
    End If

End Function

Most of the time it works, but on some machines the function hasDocument won't fire. When the control gets the focus, the function fires on that machines only for that record.

With a form.recalc the function fires for all displayed records. But when you scroll down, Access wont fire the function for the new records.

When i want to use this form as subform the form.recalc works as above, but then access redraws the subform and all control show Null again. So if the function has never fired..

I made a gif to clarify:

This Problem only happens with Access 2010. With Access 2013 the form loads also without values in the Controls, but after 1-2 seconds (which is kinda long) the hasDocument-function begins to fire for all records.

Restarting the machine often let the problem disappear for some time, but it keeps poping up now and then.

Has anyone a suggestion what can cause this behavior?

Answer 1

For anyone with the same problem: Microsoft now publish a hotfix that seams to fix this issue.

It can be found here: http://support.microsoft.com/kb/2899528