I'm getting some odd behavior, and I'm not sure if it's because I'm multisite-enabled or if it's the natural result of the plugin.
With a fresh install, as a test, I added a few tags to a page.
- Pages » Post Tags sub-menu displayed the new tag results.
- Posts » Post Tags sub-menu now also displayed these tags.
I created a post and tagged it with one of the new tags.
- Clicking "recently used tags" inside the post creation screen revealed nothing. I had to enter the tag manually.
- Posts » Posts sub-menu says "No Tags" associated with the post
- Posts » Post Tags sub-menu shows no increase in tag count
- Editing the post reveals the tag as still there, and querying for that tag returns the correct result.
Can provide screenshots if necessary.