I have the same problem,
After watching a streaming movie from bloomberg app, the movie stuck and i had to hard reset (volume+onoff+camera button), after that i had to config date time, after that i notice that my live tiles does not updates anymore ( some of them in this case the battery and stock portofoli live tile).
I have searching for a solution for 2 days now and non of the reset or uninstall of the applications worked, also have switched on of the background task, non of these helped.
does anyone tried something new yet?.
(windows phone 8)