If attached a RichTextBoxFormatBar. While playing with it, I realized I cannot change the sizes (and fonts) when the item in the ComboBox is far from the Format Bar. It seems that it considers you are leaving the format bar and it starts to fade out before you can actually select the value you wanted.
In few words, the method that fades out the bar isn't detecting whether you are just putting the mouse cursor out or selecting a value a value at the bottom (far away) in one of the ComboBox dropdowns.
In few words, the method that fades out the bar isn't detecting whether you are just putting the mouse cursor out or selecting a value a value at the bottom (far away) in one of the ComboBox dropdowns.