The users-admin application allows you to add and configure users on the system.  The "Add User" button brings up a "New user account" dialog.  The "User Privileges" tab of this dialog presents a table where each line is a checkbox and a label.  Orca doesn't announce the state the checkbox when the user navigates this table.

In looking at this with at-poke, the table looks something like this:

   table
   |
   +---table cell
   |   |
   |   +---table cell (check box)
   |   +---table cell (label)
   |
   +---table cell
   |   |
   |   +---table cell (check box)
   |   +---table cell (label)
   |
   +...

Furthermore, the selected line is handled by the selection on the table itself (i.e., the leaf table cell nodes don't seem to get focus).  A means for fixing this problem might be to script for this in a users-admin script to read the leaf nodes when the root table cell node is selected.  I'm not sure if there is a more generic thing we could do in default.py, though.