If I create panes on the fly, then save the layout to file, when I then restart the application and restore the layout, LoadFromXML throws a NotSupportedException with error "Collection is read only."

System.NotSupportedException occurred
Message=Collection is read only.
Source=System.Windows.Forms
StackTrace:
at System.Windows.Forms.SplitContainer.SplitContainerTypedControlCollection.Remove(Control value)
at System.Windows.Forms.Control.set_ParentInternal(Control value)
at System.Windows.Forms.Control.set_Parent(Control value)
at Infragistics.Win.UltraWinDock.UltraDockManager.ReparentControl(Control control, Control newParent)
at Infragistics.Win.UltraWinDock.DockableControlPane.HookContainedControl()
at Infragistics.Win.UltraWinDock.DockableControlPane.set_Container(DockableWindow value)
at Infragistics.Win.UltraWinDock.UltraDockManager.GetPaneContainer(DockableControlPane pane)
at Infragistics.Win.UltraWinDock.UltraDockManager.CreatePaneContainer(DockableControlPane pane, WindowDockingArea dockingArea)
at Infragistics.Win.UltraWinDock.UltraDockManager.SetupPaneControl(DockablePaneBase pane)
at Infragistics.Win.UltraWinDock.UltraDockManager.SetupPaneControl(DockablePaneBase pane)
at Infragistics.Win.UltraWinDock.UltraDockManager.PaneAdded(DockablePaneBase pane)
at Infragistics.Win.UltraWinDock.DockAreasCollection.InitControl(UltraDockManager manager)
at Infragistics.Win.UltraWinDock.UltraDockManager.InitializePaneControls()
at Infragistics.Win.UltraWinDock.UltraDockManager.InitializeComponent()
at Infragistics.Win.UltraWinDock.UltraDockManager.InitializeFrom(UltraDockManager source)
at Infragistics.Win.UltraWinDock.UltraDockManager.Load(Stream stream, Boolean xml)
at Infragistics.Win.UltraWinDock.UltraDockManager.LoadFromXML(String filename)
at myApp.RestoreLayout() in myApp.vb:line 1483
InnerException:

The form layout is then corrupt (e.g. I lose my UltraToolbar, and controls that were docked as Fill are now not resizing with the form)

What is the best way to recover from this (so it just gives me the layout I would have had without trying to load it), and why can it not just ignore restoring layout for any controls it can't find?  I tried saving the current layout before loading from file, so I could load this back, but this does not seem to work. :(

Thanks,
Campbell