Was playing around and noticed that the HTML Tidy you are using is out of date and doesn't support HTML5. A quick look at the official site and source code and it looks like it's not being updated.
I did find a fork though that does support HTML and does seem to be actively developed - http://w3c.github.io/tidy-html5/ Possible that you could switch to the new version or maybe just make a test build? -- Carbonize <http://forum.pspad.com/read.php?2,62270,62270> PSPad freeware editor http://www.pspad.com
