Superfish menu. Animation doesn't work.

Superfish menu. Animation doesn't work.

Hi. On my site I use Superfish menu but animation for dropdown doesn't work. They opens but without animation. It's looks like they work only on css but with delay. Maybe its from changes that I made, I doesn't use superfish.css file. I use my own css for dropdown, but JS file I'm doesn't touch. Maybe there is a conflict with other plugins (prettyPhoto, DD_belatedPNG)? How to solve this.