Sortable: tables and Firefox

I 've trying to figure how to work with tables and sortable objects.
The code above works well at IE, but in Firefox i cant make it work…
Does anyone know any kind od restrictions between FF and Scriptaculous?

Nome Campo 1 Campo 2 Campo 3 Campo 4
Nome simples 1 2 3 4
Nome simples 1 2 3 4