If you use a Story Board to hide a widget you have a bug if you use a value to make a fade out. When it is done, it is impossible after to show again the widget you had hide.
if you only use ChangeWidgetVisibilty with Hide it is OK
but ChangeWidgetVisibilty use with Hide and Value 200 or anything other 0 or "" the bug comes
I must use Animation with opacity to make a Fade off with a StoryBoard.

