t:dataTable detailStamp facet does not work well with jsf 2 ajax.
The problem is this facet is "special". Other facets are rendered just once, but this one is supposed to be rendered on every row.
It works more like a h:column that a header facet. Algorithms like visitTree and invokeOnComponent must take into account this effect.
In some parts there is some code like this:
Object facet = getFacets().remove(HtmlTableRenderer.DETAIL_STAMP_FACET_NAME);
if ( facet != null ) getFacets().put(HtmlTableRenderer.DETAIL_STAMP_FACET_NAME, (UIComponent)facet);
This works well with jsf 1.2 or earlier, but it does not work well with jsf 2 partial state saving. The facet component and its children has its initial state marked, so if the component is removed/added all state that should be restored when the view is built is lost, because the listener that tracks changes on the tree deals with this facet as a new component. In this case, PSS algorithm is correct, so we need to prevent this addition/removal doing it right, that means, do not remove it and check if the facet is a detailStamp facet and process it properly.
Note it is required to create a fix for that one in tomahawk for jsf 1.2 too but only for invokeOnComponent method.