How to reproduce :

• add this style parameter in a model :

  border-color:#f79c03/* AMETYS ("default.header.border.border-color", SKINFACTORY_MENU_BORDER) */;
      border-bottom-width:4px/* AMETYS ("default.header.border.border-width", SKINFACTORY_MENU_BORDER_WIDTH) */;

• display this parameter into a menu adding this lines in the cms-ribbon.xml file :

  > the menu corresponding to this lines is broken in the skin factory ribbon.
  
  But, if you let each parameters without a menu, the buttons corresponding appear well. The display is also ok if you replace this style 

  border-bottom-width:4px

   by this one 

  border-width:4px