jQuery UI sortable scroll helper element offset Firefox issue
Using overflow: auto; was not an option for me. I was able to work around this issue with this sort event handler:
$(...).sortable({ ... sort: function(event, ui) { var $target = $(event.target); if (!/html|body/i.test($target.offsetParent()[0].tagName)) { var top = event.pageY - $target.offsetParent().offset().top - (ui.helper.outerHeight(true) / 2); ui.helper.css({'top' : top + 'px'}); } }, ...});It is not perfect, but it doesn't require browser sniffing. Tested in IE8, Chrome and Firefox.
Edit: This is using jQuery 1.10.0 and jQuery UI 1.10.3.
I was seeing this issue and was able to solve it by removing the css rule position:relative from one of the containing divs on my page. See also: http://forum.jquery.com/topic/sortable-offset-when-element-is-dragged-and-page-scrolled-down-ff