Checked radio element creation

Checked radio element creation

Can anyone tell me why jQuery isn't checking radios built with element creation?
  2. var radio = $("<input />", {
  3. type: 'radio'
  4. }).attr('checked', true); // or .attr('checked', 'checked');

This produces

  1. <input type="radio" />

All other attributes work fine, just not checked...

Am I going mad or is this a bug? (Tried with 1.4.x & 1.5.0)