Do you see that an ajax request is sent to the server when you drop?
No I don't see any request.
It's very strange, because the demo of drag and drop support at http://livedemo.exadel.com/richfaces-demo/richfaces/dragSupport.jsf?c=dropSupport is good in my Firefox but not my implementation. I don't see my mistake.
Thank's for your help.
FireBug extension is a great tool to monitor such problems
I found my problem.
The problem is the place of my <rich:dragIndicator id="indicator"></rich:dragIndicator>, if I place it before the <h:form id="Form"> tag it's good, but not if I place it after the form tag because is id in this case is id="Form:indicator".
The div with onmousedown event generated in this case don't have the param dragIndicator.
Whith IE this case worked fine but not Firefox.
I think it's a bug.