When you delete a font you have to change the font id of all components.
Not only the fonts, but also the pictures, components...etc.
In the future version, the IDs wont be renumbered.
@ITEAD: In which version this bug will be solved?
Reviewing font renumbering.
Current versions do actually renumber the fonts but maintain the correct font number that was associated with a component.
Fonts can not be deleted while associated with a component.
Renumbering of ids have been addressed with bring top and bring bottom arrows on the toolbar.
This topic is now deemed historic and will be marked as solved.