If you add more than one slider to a page (see color picker demo for an example) the blur events are not being raised properly.
1. Click a slider handler so that it receives focus
2. Click anywhere on the page (except another slider) and see the handler loses the focus class.
3. Repeat step 1
4. Click on the second slider's handle and see it receives the focus/active class but the first handler doesn't lose it's class.
This works fine with keyboard (TAB) navigation so I assume it is a bug rather than a strange feature. It does however break any custom blur event code attached to the slider so I feel it has some importance behind it.