I just upgraded from 1.12 to 2.2.1 (the upgrade went smoothly – thank you).
In the “Visitors in Real Time” display on the dashboard, the page title displayed in the text displayed when hovering over the visited page icons does not convert HTML entities correctly.
Example: If the visited page title contains an ampersand, the ampersand is represented by the HTML entity & and any double quotes in that title become "
This used to work correctly in version 1.12 and earlier. I can’t say about any 2.x versions.
If you need to see this in my Piwik installation, please contact me by e-mail to get proper access authorizations.