The change in referred in the Q3 release notes applies to the combobox input, not the checkboxes.
The way RadFormDecorator works [when decorating checkboxes] is once it collects all such elements on the page it loops over and checks each of them if they have a class name. If a checkbox has it's own class name, the decorator will leave the checkbox as is.
That's the way it has been for about a year now -- almost the same time this check was added, the combobox support checkboxes built in.
I tested with several previous versions and none had decoration for built in checkboxes.
Now, if you use templates and
template checkboxes as shown in this demo -- http://demos.telerik.com/aspnet-ajax/combobox/examples/functionality/templates/defaultcs.aspx
-- you will be able to get the decoration. That said, you will have to take care of the actions what happens when you click on an item and so on and so forth.
To sum up, if the skinning of the checkboxes is of utmost importance, you could use templates, but if it's not that important, you can use the default checkboxes. We'll look into making the default checkboxes skinnable, yet, I can not comment on time frame of implementation.
the Telerik team
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