That’s strange, I checked the version, and it was still installed in the beta folder, so I’ve just uninstalled and re-installed the version from the site’s download page, and I can no longer get the update checker to say there’s a PDF demo.
The uninstaller does not remove samples installed via the update checker. Since the PDF demo is still installed on your computer, the update checker does not show it in the list of new updates.
You can find the demo in the Shared Documents folder, for instance at C:\Users\Public\Documents\ExeOutput for PHP\Samples