No its got nothing to do wtih the fact you are using your old dyansty. Like i said, there are two things to download these days. Patches (which you've gotten, like you said) and live tuner packs (updates pushed via online connectivity by EA). The live tuner packs cannot be received unless you purchase the EA Online Pass, or upload it (having downloaded it from the web) to your xbox via a USB Memory Stick.
You dont need to buy the full game, just the Online pass, i forget how much it costs, something like 15 or 20 bucks.