rem: this.scrollToRow(line - total / 2); 
add: this.scrollToRow(line - (last - first + 1) / 2); 
context: function xtv_ctrln (line){    var first = this.tree.getFirstVisibleRow();    var last = this.tree.getLastVisibleRow();    this.scrollToRow(line - total / 2);}
meta: 5872	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/5872/6b866a92208c3fedf42bd2e47303c1aa4424e1cc/tree-utils.js/buggy/extensions/venkman/resources/content/tree-utils.js