Crossfire causes slow shut down?

Its been happening for quite a while now and finally I'm bringing up this problem. Whenever I run Crossfire, it causes my computer to shut down extremely slow when I want to restart or shut down my computer - give or take maybe 15-20 minutes to shut down. But when I use my computer without going on crossfire at all, then my computer shuts down fine. Why does this keep happening?

Also, recently I reformatted my hard drive and brought my computer settings to factory default. It has happened before I reformatted, and it still happens after...