Well , I'm Ashamed.
It worked with the employee database , so i scanned my prior test database
and it occured that in some tables it , indeed , worked , but on some others
, didn't , and as said previusly , in some others , the application gets
locked saying something about multiple rows in a singleton select.

A fine and interesting Work In Progress

Javi
EntreBytes S.L.
Ontenient , Spain
ERP Development.