Cursor is not visible in Firefox if CKeditor is initially hidden

hidden_ckeditor.js

/*
If you have a CKeditor input field that is initially hidden, the cursor will not show up in Firefox 3.6 when you make it visible.

You can work around this by setting the contentEditable attribute of the iframe body to false and back to true.

Example jQuery snippet:
*/

$("form.ckeditor iframe").each(function (iframe) {
    $(iframe[0].contentWindow.document.body).attr({ contentEditable: false }).attr({ contentEditable: true });
});