Bug appear in Firefox browser. Not in Chrome nor IE. (Didn't test other browsers).
Once you use some jquery sortable functions:
$( "#sortable" ).sortable();
$( "#sortable" ).disableSelection();
on html elements like (i.e. td or li)
The css active (also focus?) will stop having an effect from now on (as if it's not there).
So if you have a sortable li (like in site example) and a css command:
and u use
$( "li" ).sortable();
The css above will stop working.
As seen in this fiddle: http://jsfiddle.net/9pqywyxm/3/
In fiddle when you try to change li position:
In Chrome background will become green as the active css specifies.
In Firefox nothing will happen to background- as the active css is ignored.
I recommend trying in chrome and Firefox to see the difference.
If you have any questions feel free to email me: email@example.com