See also Orca bug #465097 which is blocked by this issue.
http://bugzilla.gnome.org/show_bug.cgi?id=465097

(There doesn't seem to be an entry in the "Found in version" list on this
bug report web page for OOo-dev 2.3.0).

This is with OOo-dev 2.3.0 (build #223) Linux RPMs on Ubuntu Gutsy
(with all the latest updates and with Orca from SVN HEAD).

I've been working through the OOo database tutorial at:
http://sheepdogguides.com/fdb/fdb1tableone.htm

At one point you will come to:

" ... The table design window should close, and you should see a project 
manager window with three main panes: Database, Tasks, and a third, 
probably labeled "Forms" at the moment. In the pane labeled "Database" 
(left column) click on "Tables", ..."

I tried to do the keyboard equivalent of that. You can navigate entries
in this "tree" with the Up and Down arrow keys, but Space and/or Return
do not select them.

That's because they are labels. Here's the accessible component hierarchy 
at this point:

+-name='soffice' role='application' state='' relations=''
  +-name='FDB004 - OOo-dev Base' role='frame' state='ACTIVE ENABLED RESIZABLE
SENSITIVE SHOWING VISIBLE' relations=''
    +-name='FDB004 - OOo-dev Base' role='root pane' state='ENABLED SENSITIVE
SHOWING VISIBLE' relations=''
      +-name=None role='panel' state='ENABLED SENSITIVE SHOWING VISIBLE'
relations=''
        +-name=None role='panel' state='ENABLED SENSITIVE SHOWING VISIBLE'
relations=''
          +-name=None role='panel' state='ENABLED SENSITIVE SHOWING VISIBLE'
relations=''
            +-name=None role='panel' state='ENABLED SENSITIVE SHOWING VISIBLE'
relations=''
              +-name='IconChoiceControl' role='tree' state='ENABLED FOCUSABLE
FOCUSED SELECTABLE SENSITIVE SHOWING VISIBLE MANAGES_DESCENDANTS' relations=''
                +-name='Tables' role='label' state='ENABLED SELECTABLE SELECTED
SENSITIVE SHOWING TRANSIENT VISIBLE' relations=''