Table doesn't show generated columns in Liferay portlet

Hi All,
I’m working on Vaadin portlet hosted on Liferay 6.2-ce-ga4. Everything works good, but when I try do display table with generated column (to be more precise viritin MTable), generated column does not appear on the screen.
On server side it exists (all properties are available) but on client side I see nothing.
Is that any way to activate Vaadin client debug console inside Liferay portlet?

Regarding last question - answer is very simple. Just add “?debug” to your potlet URL. Anyway main topic is still unanswered.

It seems that there is a problem with Viritin or with setColumnHeaders() Vaadin method.
When I use withColumnHeaders() method without setVisibleColumns(), headers are added as properties.
After replacing withColumnHeaders() with series of setColumnHeader() methods, generated column appeared!