rem: if (!cell.value || (row.value == -1)) 
add: if (!cell.value || (row.value == -1)) 
context: function userlistdnd_dstart(event, transferData, dragAction){    var col = new Object(), row = new Object(), cell = new Object();    var tree = document.getElementById('user-list');    tree.treeBoxObject.getCellAt(event.clientX, event.clientY, row, col, cell);    // Check whether we're actually on a normal row and cell    if (!cell.value || (row.value == -1))         return;    var user = tree.contentView.getItemAtIndex(row.value).firstChild.firstChild;    var nickname = user.getAttribute("unicodeName");    transferData.data = new TransferData();    transferData.data.addDataForFlavour("text/unicode", nickname);}
meta: 3298	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/3298/c77963cf4d802288ff8a64cba74206f7ee6133b9/static.js/clean/xul/content/static.js