@esmi Already use the TwentyTen theme, and yes, refreshed plugins folder per your post in another thread.
I’ve also discovered that if I open a post from my blog site using the Edit link or if I open a draft that’s listed on the Dashboard I get an editor that looks like it should (i.e., the right side bar is there with all the tag fields, etc.) as opposed to the editor I get from just clicking on Add Post, which just has what appears in the center.
ETA: In the editor, there appears to be a problem differentiating between the visual editor and the HTML editor.