tabindex -1 not working in firefox

I am testing an application in firefox. When i hit tab it focuses the body of firefox. If i it tab again then the next item in header. now while next item is having focus if i do shift + tab it goes back to body and if i do shift + tab again it comes back to same item. It didnt move focus to address bar and goes in loop between body and next item if i keep pressing shift + tab.

I tried using tabindex: -1 and -moz-user-focus: ignore at body but no luck. I dont get this issue with other browsers.

Any idea how do i fix this issue?

Source: stackoverflow-javascript