You can get it at the site below. Go to the "RPG Maker 2003 Patch Update" section and pick "Patch Update RM2k3 1.09a (Eng)". This patch fixes some minor issues (major if you like using classes a lot).
THIS WILL REINSTALL RPG MAKER 2003. It will also cease to be RPG Advocate's version, which is what I consider to be the "official" version. You may have troubles with RTP after installing.. that means you get to reinstall THAT as well!
I don't recommend updating yet unless you REALLY need the bug fixes. I would wait until RPG Advocate translates the patch on his own.