Thanks, that seemed to work. One question, do I have set each layer's zoomlevelset to the custom levels or does it do it automatically?
For instance, I have a lot of layers set up like this:
inMemoryFeatureLayer.ZoomLevelSet.ZoomLevel01.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level20;
Will the above ApplyUntilZoomLevel work for the custom levels as well?