Deleting wrong chars in the source editor of CKEditor

I called the link: http://ckeditor.com/demo in the javafx.scene.web.WebView and then pushed the Source button (top-left corner of ckeditor).
I placed the cursor on some text and tried to delete a few chars, but other chars got deleted.
Also, typing chars adds the new chars at a wrong location sometimes.

This problem is both in the 2.2.0.b17 and in 2.2.0.b19.