Make required radio button when product is free

[Loubyloo]

I followed the instructions for adding a third radio button as display only so that customer have to choose an option, this worked perfectly on nearly everything BUT when I have an item that is FREE this does not appear to work. The make selection radio button which should be display only with the radio button in black is not doing this and is only letting you choose the 3 selections. You can see the link here http://digitaldelightsbyloubyloo.com...oducts_id=2407. Any help or suggestions please ?

[Ajeh]

Did you mark the Attribute as:
Display Only
Default