Visual Editor Fails on 1 site of Multisite

I finally got sick of the visual editor not working on my multisite installation of 3.1, I reinstalled the relevant parts of WP, deleted and re-loaded my plugins and finally, got it working on 2 out of the 3 sites in my multisite installation. Everything is great on two sites, still having the same problem on the third. I really don’t get how that can be, considering it’s all part of one installation. I’ve updated everything, still no go.

Ideas?