The problem is you don't reset the queue. So if you mouse over/ mouse out fast. It will show nothing. Try this:
$('body').on("mouseenter", ".image a img", function () {
$(this).stop(true, false).fadeTo('slow', 0.7);
})
.on("mouseleave", ".image a img", function(){
$(this).stop(true, false).fadeTo('slow', 1);
});
Which will reset the queue, but not jump to the end. Also, you can use the LIVE element to keep the event alive on all items which change. Which is on in the new jQuery since 1.8