There is not resolved issue about "Now playing" progress-bar in htmlUI.
Unfortunately I'm not able solve it quickly.
I've understand the code only a short time and there probably should be
added some JavaScript (e.g. AJAX-like) communication channel from
JavaScript to scheduler
- because htmlUi seems to show right information only after page
request, if there is no new page request, progress-bar have not enough
information to show after several clip2clip transitions.