I'm having the same issue with Black Ops 1 (PS3).... I sold my original Black Ops game, but have since bought another one (I missed the flame thrower... what can I say). I have gone into Account Management > Transaction Management > Download List and re-downloaded the original map packs (First Strike, Annihilation, and Escalation) several times because they either don't show up as being downloaded or they aren't showing up in-game.
I have gone in and deleted all of the Saved Utility and Game Utility information, but NONE of the map packs are showing up. I don't remember for sure, but I want to say that I bought the season pass for Black Ops 1. Regardless, there is no downloadable content in-game anymore and re-downloading the map packs from my account is obviously not working.
Any suggestions? Thanks in advance