When MC22 in Standard View is set to View a custom Skin, everything displays as expected, except in the "Tools, Options" menu window, where the Frame_CheckBox.png item is ignored and MC displays its internal default version of the CheckBox (a dark-framed white square with a green checkmark inside).
For example: The Aruba skin's customized CheckBox is a black square inside a square. That displays properly in the general menus such as in the "Services & Plug-ins, Scheduler, Add Task" window, where you can see that the Radio Buttons and the Check Boxes use Aruba's custom skin elements. However, looking at the "Tools, Options" menu shows all of the Check Boxes using the default green checkmark inside a white square with a dark outline.
To note, I have not found any Radio Buttons in any the Options menu items and so cannot confirm if they are also affected by this bug (set to use a default Radio Button instead of the custom skin Radio Button), but you may want to look for that when reviewing the source code.
Thank you.
