Pull out the spring and make sure the black sheaths on the spring are still on there correctly, that seems to be a common problem when it comes to clicking it is just that black oven wrapped sheath folding that causes the clicking. If that isnt the problem check to see if the clicking is coming when the fork rebounds, if so send it out to have the dampener rebuilt.
If you are the original owner you may be able to give Sram a call and see what they could do about a warranty. If not your best bet is to send it out to get it rebuilt, first check the spring though.