Sortable very slow on linux [Firefox/Epiphany] not Opera

Sortable very slow on linux [Firefox/Epiphany] not Opera


Hi,
When i drag element of a sortable exemple, the element is very laggy,
but when i release it, he came back normaly :
http://docs.jquery.com/UI/Sortables
In this page i don't have any problem :
http://docs.jquery.com/UI/Draggables
Have you notice some bug ?