Not working in Opera 9.1, on Linux/OSX:

JavaScript - http://www.64funsolutions.ca/chessdiagram/
Event thread: mousemove
Error:
name: TypeError
message: Statement on line 1: Object cannot be converted to primitive value
Backtrace:
  Line 1 of eval script 
    return ! ! fn && typeof fn != "string" && typeof fn[0] == 
"undefined" && /function/i.test(fn + "");
  Line 1 of eval script 
    if (window == this)
    a = a || document;
if (jQuery.isFunction(a))
    if (typeof a == "string")
    return this.setArray(a.constructor == Array && a || (a.jquery || 
a.length && a != window && ! a.nodeType && a[0] != undefined && 
a[0].nodeType) && jQuery.makeArray(a) || [a]);
  Line 1 of eval script 
    if (window == this)
    a = a || document;
if (jQuery.isFunction(a))
    if (typeof a == "string")
    return this.setArray(a.constructor == Array && a || (a.jquery || 
a.length && a != window && ! a.nodeType && a[0] != undefined && 
a[0].nodeType) && jQuery.makeArray(a) || [a]);
  Line 1 of eval script 
    elm = jQuery.iDrag.dragged;
elm.dragCfg.init = true;
dEs = elm.style;
elm.dragCfg.oD = jQuery.css(elm, "display");
elm.dragCfg.oP = jQuery.css(elm, "position");
if (! elm.dragCfg.initialPosition)
    elm.dragCfg.oR = {x : parseInt(jQuery.css(elm, "left")) || 0, y : 
parseInt(jQuery.css(elm, "top")) || 0};
elm.dragCfg.diffX = 0;
elm.dragCfg.diffY = 0;
if (jQuery.browser.msie)
    elm.dragCfg.oC = jQuery.extend(jQuery.iUtil.getPosition(elm), 
jQuery.iUtil.getSize(elm));
if (elm.dragCfg.oP != "relative" && elm.dragCfg.oP != "absolute")
    jQuery.iDrag.helper.empty();
clonedEl = elm.cloneNode(true);
jQuery.iUtil.purgeEvents(clonedEl);
jQuery(clonedEl).css({display : "block", left : "0px", top : "0px"});
clonedEl.style.marginTop = "0";
clonedEl.style.marginRight = "0";
clonedEl.style.marginBottom = "0";
clonedEl.style.marginLeft = "0";
jQuery.iDrag.helper.append(clonedEl);
if (elm.dragCfg.onStart)
    dhs = (jQuery.iDrag.helper.get(0)).style;
if (elm.dragCfg.autoSize)
    else
    dhs.display = "block";
dhs.marginTop = "0px";
dhs.marginRight = "0px";
dhs.marginBottom = "0px";
dhs.marginLeft = "0px";
jQuery.extend(elm.dragCfg.oC, jQuery.iUtil.getSize(clonedEl));
if (elm.dragCfg.cursorAt)
    elm.dragCfg.nx = elm.dragCfg.oR.x;
elm.dragCfg.ny = elm.dragCfg.oR.y;
if (elm.dragCfg.insideParent || elm.dragCfg.containment == "parent")
    if (elm.dragCfg.containment)
    if (elm.dragCfg.si)
    dhs.left = elm.dragCfg.oC.x - elm.dragCfg.diffX + "px";
dhs.top = elm.dragCfg.oC.y - elm.dragCfg.diffY + "px";
dhs.width = elm.dragCfg.oC.wb + "px";
dhs.height = elm.dragCfg.oC.hb + "px";
jQuery.iDrag.dragged.dragCfg.prot = false;
if (elm.dragCfg.gx)
    if (elm.dragCfg.zIndex != false)
    if (elm.dragCfg.opacity)
    if (jQuery.iDrop && jQuery.iDrop.count > 0)
    if (elm.dragCfg.ghosting == false)
    return false;
  Line 1 of eval script 
    if (jQuery.iDrag.dragged == null || jQuery.iDrag.dragged.dragCfg.prot 
== true)
    var dragged = jQuery.iDrag.dragged;
dragged.dragCfg.currentPointer = jQuery.iUtil.getPointer(e);
if (dragged.dragCfg.init == false)
    dx = dragged.dragCfg.currentPointer.x - dragged.dragCfg.pointer.x;
dy = dragged.dragCfg.currentPointer.y - dragged.dragCfg.pointer.y;
for (i in dragged.dragCfg.onDragModifier)
    dragged.dragCfg.nx = dragged.dragCfg.oC.x + dx - dragged.dragCfg.diffX;
dragged.dragCfg.ny = dragged.dragCfg.oC.y + dy - dragged.dragCfg.diffY;
if (dragged.dragCfg.si && (dragged.dragCfg.onSlide || 
dragged.dragCfg.onChange))
    if (dragged.dragCfg.onDrag)
    if (! dragged.dragCfg.axis || dragged.dragCfg.axis == "horizontally")
    if (! dragged.dragCfg.axis || dragged.dragCfg.axis == "vertically")
    if (jQuery.iDrop && jQuery.iDrop.count > 0)
    return false;
  Line 1 of eval script 
    if (typeof jQuery == "undefined" || jQuery.event.triggered)
    event = jQuery.event.fix(event || window.event || {});
var returnValue;
var c = this.events[event.type];
var args = [].slice.call(arguments, 1);
args.unshift(event);
for (j in c)
    if (jQuery.browser.msie)
    return returnValue;
  At unknown location
    [statement source code not available]