There is one Zurich only, and it's 1.3. There's no need to uninstall the old one.
It's will run regardless if you have patched FS9 to use more than 2GB of RAM (of course, with only 1GB, it doesn't make much sense to patch it).
But, as explained in the announcement message, it's not compatible with FS9 CD protection. So, if you want to use it, you need a no cd patch for FS9.
The new installer for the stand-alone Addon Manager has been updated already, it will now automatically install the correct version, depending on what kind of FS9.EXE you have.
http://www.fsdreamteam.com/forum/index.php?topic=298.msg1594#msg1594