HP-ALM (Mercury) OTA Unable to Change Test Instance Status

In the Test-Management application ALMs' OTA API; I have the below statements (in VB-script):

'save run
Private Sub saveRun(ByVal labTest As Object, ByVal head As Integer, ByVal tail As Integer)
    Dim status As String: status = findStatus(labTest, head, tail)
    labTest.status = status
    labTest.post
    Dim run As Object: Set run = labTest.RunFactory.AddItem(Null)
    'run.UnLockObject
    run.name = labTest.name
    run.status = status
    run.post
    run.CopyDesignSteps
    run.post
    doSteps run.StepFactory.NewList(""), head, tail, 0
End Sub

The test-instance was derived inductively from the root Test-Lab folder. All children of the test-instance are amendable without a problem (Run, Step).