New copy of Aperture won't accept my purchase reg code

I bought Aperture in 2010, when Ap 3 first came out. A couple of weeks ago, my hard drive and logic board on my MBP both died. After the repair, I downloaded a trial copy of Aperture and tried to put in my purchase code; it is not accepted. I then entered the trial code--accepted--and tried to use the purchase code. No joy.

Help!

Joel