Question

Why does delay() work here:

$('#tipper').mouseout(function() {
  $('#tip').delay(800).fadeOut(100);
});

But this fails to delay:

$('#tipper').mouseout(function() {
  $('#tip').delay(800).css('display','none');
});

// EDIT – here’s a working solution

// EDIT 2 – some bugs fixed

$('#tipper').mouseleave(function() {
  setTimeout( function(){
    $('#tip').css({'display','none'});
       },800);
});

Answer 1

delay() works with the animation (fx) queue. Changing a css property does not work via that mechanism, and thus is not affected by the delay directive.

There is a workaround — you can inject the property change as a queued operation, like this:

$('#tip')
  .delay(800)
  .queue(function (next) { 
    $(this).css('display', 'none'); 
    next(); 
  });

Also, you should probably be using .hide() instead of .css('display','none').

Here’s a working example: http://jsfiddle.net/redler/DgL3m/