Cool! got it!
finally I came across a post which fully clarified my understanding on this very little issue and convinced me to further investigate the keybindings. That was the solution. Focus was confusing me, but in fact although most of us know that table is a single component instead of a sum of cell components, somehow I thought focus had to be the point, but it was not, since table is a "single" component, therefore establishing a focus policy is useless, and although the methods are there to attach focus policies I got none to be called, which means that somewhere the Event Dispatching
Thread must skip it from the focus management (on this if anyone has anything to say, any advise is greatly appreciated to deepen my understanding in the Swing thread schema). So basically what I did was to override the ENTER keybinding associated with the table ("selectNextRowCell") and attach a custom action to the Action-/Inputmap which would manually handle selection by calling the following methods in the JTable:
setColumnSelectionInterval(c,c,true,false)
setRowSelectionInterval(r,r,true,false)
which completely fullfilled my needs. By the way additionally setRowSelectionAllowed and setColumnSelectionAllowed must be set to false, in order to avoid full column/row selection, in favor of single cell selection.
Hope this helps someone. So stupid but took so much time! Hope no one else will spend as much as I did!
thank you again.
Carlos.