When using jQuery Update, field Widgets are permanently disabled, CCK becomes unusable.

When using the jQuery update module, the code in content.js

    $(this)
      .html(html)
      .attr('disabled', disabled ? 'disabled' : '');

This will always disable the widget.

The code needed is:

    $(this).html(html);

    if (disabled == true) {
      $(this).attr('disabled', 'disabled');
    }
    else {
      $(this).removeAttr('disabled');
    }