Missing Placement Properties in Label Manager after runnning Tool

[RobertWilcox]

I have created a Command in VB.Net to remove all Label Classes from a specified layer. This works fine with the standard label engine, however, when I have the Maplex label engine running, I get an odd result. There is just a blank box for the Placement Properties:

Here is the code:

pFLayer = pMap.Layer(0) 'Just manipulating the first layer for now, a polyline FC.
        
        pGeoFL = pFLayer
        pAnnoLayerPropsColl = pGeoFL.AnnotationProperties
        pAnnoLayerPropsColl.Clear()
        pLabelEngineLayerProps = New LabelEngineLayerProperties
        pAnnoLayerProps2 = pLabelEngineLayerProps
        pAnnoLayerPropsColl.Add(pAnnoLayerProps2)

Is there something I am missing? Am I working at too low of a level?

Thanks for any advice.