I KNOW. I mean, I love Lion's autocorrect; it's a great new tool it just sometimes acts like a complete tool and gives me the wrong words.
I have only one complaint with it: I want to be able to define my own corrections. You know, like how the applications of the iWork suite let you define autocorrections. I want that SYSTEM-WIDE.
I'm not sure of the priority but you might be define some manually in System Preferences » Language & Text » Text tab.