Issue with sortables drag and drop

Issue with sortables drag and drop


Hi,
I wrote 2 sortables (<UL>s) with the same code and they have only ul1
has an element but ul2 is empty. I kept moving the <LI> element from
ul1 to ul2 to ul1 ... at a moderate pace and at some point the element
doesn't move. It just gives this error :
[Exception... "Could not convert JavaScript argument" nsresult:
"0x80570009 (NS_ERROR_XPC_BAD_CONVERT_JS)" location: "JS frame ::
http://phpdev.talkpoint.com/qps/libs/jquery/jquery.js :: anonymous ::
line 23" data: no]
[Break on this error] jQuery.swap(elem,props,getWH);return
Math.max(0,val);}return jQuery.curCSS(elem,...
Here's the code i use to initiate them both :
By the way, both the UL elements have classes flora and qrow_group
hopefully this will keep the code indented ..
    $('ul.qrow_group').sortable({
        connectWith : ['.flora'],
        tolerance : 'pointer',
        items : '.qrow_item',
        placeholder : 'qrow_group_helper',
        zIndex : 100,
        revert : true,
        update : function(e, ui) {
            var id1 = this.id.substring(13);
            var pollId = $('#poll-'+id1+'-id').val();
            var pollId2 = '';
            var children = $(this).children();
            if (ui.sender) { // Question was sent from another poll
                var draggedEl = ui.item[0].id;
                pollId2 = $('#poll-'+draggedEl.substring(13)+'-id').val();
                // Put the question back to the source if target has more than <X>
questions
                if ((10 <= children.length)
                || ((2 <= children.length) && (id1 != 'event_pool_list')
                    && (undefined != $
(children[0]).find('.rating_scale_useless_class')[0]
                    || undefined != $(children[1]).find('.rating_scale_useless_class')
[0]))
                || ((2 <= children.length) && (id1 != 'event_pool_list')
                    && (undefined != $
('#'+draggedEl).find('.rating_scale_useless_class')[0]))
                ) {
                    $('#'+ui.sender[0].id).append($('#'+draggedEl)[0]);
                    return false;
                }
            }
// code truncated ...
            $.post('index.php', {
                    task: 'order_questions',
                    poll_id: (null == pollId)? '': pollId,
                    poll_id2: (null == pollId2)? '': pollId2,
                    questions: ids
                },
                function(data) {
                    //alert(data);
                    // Attach the update timer after the request is complete
                    timerObj = setInterval('updater()', $('#ajax_timer').val());
                    if ($.browser.msie) {
                        window.location.reload(true);
                    }
                }
            );
            return;
        }
    });
Am I doing anything wrong here ? If so, can you guys please point mein
the right direction. It could be a bug but I have a feeling it's me.
Thanks in advance
Moazzam