OMG! This is weird. Can someone please help me!

Hi
I have an unusal problem relating to my nav bar menu. It is displaying duplicate text, for example if I have an about me page you would expect the menu tab to display “About Me” but infact it is displaying like this About Me”>About Me. It is duplicating the text with the html code inbetween.
Does anyione know why this is happening and how to resolve it? I have the all in one seo pack puggin installed and the funny thing is when I disable this puggin the problem goes away, unfortunately I need this pluggin.

Any help would be greatly appreciated.

Thanks