DCharts and navigator (Canvas problem?)

Hi guys,
May be you can help me. I have in my application some custom component (like DCharts) using canvas. I use Vaadin 7.1 and a navigator.
First time I navigate to my view displaying my component, there is no problem, every thing is alright but if navigate to another page and come back to this one, my component doesn’t display. If I look inside the html code I see my div but it’s empty and I have to refresh my page to display it.
I read this thread
and I think I have the same problem.
To test I tried to draw two chart and only the first is displayed.

Does somebody could help me because it’s really problematical.