I haven't played Halo 3 since 2008, but then bought Halo 3: ODST today.
I got a few achievements from Mythic maps and I unlocked the Kitana, and suddenly, it got locked again.
I got 1020 Gamerscore from Halo 3, and I'm really confused. I don't have the Security Helmet as well. Everything else, however, I do have.
Anything I can do to get it back?