Obama later withdrew the nominations of the two whom he illegally appointed. He appointed two replacements, who, along with the three previously appointed and awaiting confirmation, were confirmed by the Senate on July 29, 2013.
Any decisions made by the board when the two served illegally are null and void. I believe there were some 800 decisions during that time.
Those on the board at this time are there legally and their decisions stand, unless later found specifically unconstitutional.
Thank you! :-D