(xoben @ Feb. 24 2012,07:22)
'Greyed' item means 'not used', so 'checked' or 'unchecked' has the same result.
I am not 100% with you on this one.
Grayed most often means "disabled", "read-only", not possible to access at this time.
Following the logic of the "Deep Hidden" if we say that at this point of operation it is not used, and the checkbox specifies whether it is used or not, it should be unchecked and grayed out, meaning it is not used and cannot be changed at this point of time.
Another example of misleading ui is:
Create a new image, select 'Bootable' menu. 'Save Boot File..." menu item is not disabled but it should. It also has "..." in the name, meaning there will be another dialog coming after a user clicks on the item. However nothing comes. If the application has menu item not disabled, then when a user clicks the item there should be a message box saying that the "current image is not bootable and there is nothing to save" or similar. Having "..." on a button or menu and showing nothing after it is clicked/used is wrong design.
There are several places in the application that do nothing when you click on the button/menu item. They either should be disabled or should show a message why it is not possible to access this functionality right now.
Those things do nor really prevent or do something that it supposed to do, especially for expert users. However UI suppose to guide and be intuitive. And that's what I am arguing about right now.