QuickDesigner: Navigator might display no id

Steps to reproduce:

• create a Quick Application from template
  • make sure main components have no id property set (ApplicationWindow and MainForm in my case)
• switch to Designer
• check Navigator
  • should display ApplicationWindow and MainForm as no id is set
• double-click on one of these, so that the value becomes editable
• click somewhere else
• instead resetting to the old value the navigator now displays an empty label