How to reproduce:

• Add some default values on a content type (directly in the XML file, not using the tool)
• Open the content types editor
  • the default values are displayed when selecting the attribute => OK
  • the default values of complex data (ex: geocode) are not well displayed => KO
• Modify the attribute
  • In the dialog box, there is no way to modify, add or delete default values => KO
  • Make any other modification
• Save the modifications
  • The default values of the attribute has been deleted => KO