one editor destroyed,another created,combo box can't be opened

[mahuzi]

When one editor created in page,you click to open a toolbar combo box ,like font, fontsize etc. destory the editor,then created another editor,and you click to open a toolbar combo box again,it can't be opened. and I find this problem in ckeditor demo(sample) too. demo:http://ckeditor.com/demo you click a combo box in "Editor with all features" demo. then you change to "Interface color" demo to click any combo box,it can't be opened. firebug show some error: "this.$ is undefined http://ckeditor.com/apps/ckeditor/3.0.1/ckeditor.js?1257207309 Line 11"

[fredck]

DUP of #4552