To my reckoning, Acceleration is always with SP2. I bought Acceleration when it was first released and there are no more FSX Service Packs to follow. Even if I download SP2 for FSX, it won't install. If I install SP2 then Acceleration, it will uninstall SP2 before installing itself. The 1st one you have will be the same as the one from Amazon.com as far as I know.

I have a lot of addons for FSX and they all work fine for me with Acceleration installed.

Mark