I really like this plugin, but I had to deactivate it.
I recently noticed that when I tried to edit an already published post/page, or even an unpublished post/page that had been saved or auto-saved as a draft (then you exit the editor and later come back to edit again), that many of the text fields would not accept any keyboard entry. The affected fields include, but may not be limited to, the title, the url slug, the text area when set to the html tab (but not when set to the visual tab), the Simple Tags plugin field, the scheduling/published-on date/time fields.
For some reason this problem does not affect freshly started new pages or posts. But as I said, once a post or page has been published, or saved, then when you go back to edit it the problem arises.
So I went through my plugins, deactivating them one by one until the problem went away. It was the deactivation of this plugin that caused the problem to disappear.
I can't use this plugin until this bug is fixed.
I'm running WordPress 3.0 with the Thesis 1.7 theme.