In firefox, when you apply .focus() to an element, the element receives the focus but sometime the dotted outline does not appear. Maybe its not jQuery's fault but the error is with Firefox.

To see the bug in action

http://jsfiddle.net/spiderplant0/UEuMP/

Press runs and

then before you try anything else, click on the button.

You should see the link get a yellow background but no dotted outline.

Now press TAB a few times and when the link receives focus, it will get both the yellow background and the dotted outline.

It seems that after you press TAB, the bug dissapears as clicking the button now causes the dotted line to appear.

Windows 7, 64 bit, JQuery 1.10.2, Firefox 21