I have absolutely the same problem. In my case the suggestion for the last row of the list pops up and works fine, but for all previous rows no pop-up is shown, though the controller and the suggestionAction are invoked and the returned result is correct.
I would appreciate some comments on this issue. Does anybody have a working solution. Or is it just not possible to work with a suggestionBox within a rich:dataTable?
Similar problem here.
I get a NullPointerException because the table iterator object ("object" in your example) is null.
Initially I had the suggestion boxes and my rich:dataTable inside an <h:form> Tag and the suggestion boxes did not work.
Now I have changed the form to an <a4j:form>, and the suggestion boxes inside my editable list work correctly.
I did not make any other substantial changes. Maybe this could help.