Hi when you add some RibboncheckedBox in a RibbonComboBox, the RibbonComboBox dropdownlist has a wrong width.
It seems it was because of the RibboncheckedBox.MeasureSize() method. In this case the 'SizeMode' is Set to 'DropDown' and never evaluated, so the RibboncheckedBox will return only the CheckBox size (the square, not the control).
it could be corrected by adding a single ligne
RibbonCheckedBox.MeasureSize() near Line 266
case RibbonElementSizeMode.DropDown : //CBoury : Correct RibbonChekedbox Width
w += iwidth + lwidth;
w += iwidth;