I posted a new bug against the extended datatable.

https://jira.jboss.org/jira/browse/RF-8212

Short story:

Two grids on a page.  Top grid is selectable and is master.  Bottom grid is not selectable (selectionMode="none") and shows some details about the top grid's selection.  When the bottom grid is reRendered, the top grid's keyboard selection stops working.

More details on the jira link.