Yesterday I updated to firefox 13 and I notice that this property is not any more supported by firefox 13, jquery.ui.css make use of this, and now I have all jquery ui eleme
Normally, you just should have to do nothing, because the jQuery-UI css files declare the border-radii the correct way.
-border-radius:xxx
border-radius:xxx
This way you shouldn't even notice the change. So I can't believe that you will miss the round corners without having altered the original stylesheet. Perhaps your problem lies somewhere else?