Required fields inside a table

Hello, I’m pretty new with vaadin but I managed to do the basic stuff. Actually I’m using through activiti.

I’m having a problem when I try to set a field (example combobox) as required inside a table in a form. I can set the required icon and the message over the field but I dont recieve the error indicator message on submit … . I’m using the CustomField addonn where I just define the customField and add it to the table as an item.

Appreciate any help.
Thanks in advance