Strange behavior on categoris.php sidebar

I’ve made the catagories.php.

When i’m on https://www.aficionado.dk/ – the ‘on-mouse-over’ on my categories looks ok.
But if you press a category, and then look at the ‘on-mouse-over’ on my catagories, suddenly the ‘on-mouse-over’ text is off, and som htlm code is also displayed ( and ).

How can i correct this ?
Any help is really appreciated.