firefox strange redirecting

dear sirs,
i will appreciate very much if someone helps me. suddendly today, i am facing a problem with my site. when i visited with firefox and i click to read a news item it goes me back, in homepage, whatever i visit in my site, it loads for seconds and in seconds goes me back. these happens only with firefox. i have the latest version of wordpress. i disable all the plugins. the problem remained. when i changed the theme, the problem gone. so i supposed that problem maybe is from a theme, but i am not sure. the theme is from proffesional site and i bought it.. what might be thew problem. it happends only with firefox and when you click something, it takes you back to previous page you have been or previous site. if someone can help me with some ideas, i will appreciate!