I created a encore project a few months ago and when played in WMP you couldn't scrub the timeline or fast forward/rewind. I check the user settings and activated 'All' which seemed to cure the problem. However I've just created another disc in the series using the same settings and once again I can't scrub the timeline. Moreover playing the first project disc again now that too won't scrub.
If you pick up the play head button and move it down or back along the timeline it just flicks back to the current time.