That error isn't saying you have the wrong version of ACE, it's an ACE module that tells you what addons you or the server are running that the other isn't. As long as you are running the ACE version from the Command Announcements Mod Updates you are running the correct version of ACE.
In this case, you are missing mad_signs, ibr_lingorfuel, fallujah etc. that the server is running. Those are .pbo's related to the map pack that the Assault server runs that SSG Purcell posted.