Addon with canvas with fabric.js

Hello, I'm making a timeline addon using canvas with the help of fabric.js library. In plain html i can drag object placed on the canvas, in GWT it is the same, but as soon as I "wrap" it in vaadin addon - events dont work unfortunately. It paints, but no events (I mean drag objects within canvas by mouse). No errors in browser console etc. I googled a lot and almost found nothing but a discussion in google groups about the same thing. They thought that it is because of css rules that canvas element inherint from vaadin ones. I think this is the reason. Can someone help me to find out how to solve it? Thanks!