If you are looking to make this plug-in work for IE7 (it already works on IE8), you only need to update three things in the plug in:
1 & 2. In the open function, update the line: contextMenu.css({ top: this.get_mousePosition().top - 10, left: this.get_mousePosition().left - 10 }); by adding position: "absolute", and more of a buffer to the left mouse position like so: contextMenu.css({ position: "absolute", top: this.get_mousePosition().top - 10, left: this.get_mousePosition().left - 50 });

1. Also in the open function, add the line: contextMenu.setAttribute("className", this.get_style().containerCssClass); directly after the line: contextMenu.setAttribute("class", this.get_style().containerCssClass); IE7 doesn't support the "class" attribute when setting it this way, so you need to use "className".