Test Case Boilerplate
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HTML
<div id="test"></div>
JavaScript
jQuery(function($){
var c = $("<span/>").appendTo($("#test"));
c.css('background-image','url(http://abc.com/123.gif)');
console.log("value: " + c.css('background-image'));
console.log('detaching');
c.detach();
console.log('attempting background-image change');
c.css('background-image','url(http://abc.com/blah/123.gif)');
console.log("value: " + c.css('background-image'));
console.log('attaching');
c.appendTo($("#test"));
console.log('attempting background-image change');
c.css('background-image','url(http://abc.com/blah/123.gif)');
console.log("value: " + c.css('background-image'));
});