jquery Flashes Div Element Before Executing .hide() and .fadeIn() Methods

Hide using CSS and then fade it in when required :

css :

.items {
   display:none;
}

JavaScript

$('.items').html(response).fadeIn();

You could using the opacity instead if you want to keep the dimensions of the element intact:

$('.items').html(response).css({'opacity':0}).animate({'opacity':1});