One way to fix it is to create the KEY-DOWN trigger (it moves the focus to the next record); it should contain only one line of code: NULL; (i.e. don't do anything).
This would, though, prevent user from going up and down ALWAYS (which is not good as well), so you may decide to allow going up and down only if user is on the first or last item in a record. Otherwise, do nothing. Something like this: assume that 'LOC' is the last item in the 'DEPT' block:
Code:
if :system.cursor_item = 'DEPT.LOC' then
down;
else
message('Disabled: you are not on the last item');
null;
end if;
Default navigation in a block can be set only for the first or the last item in a record, and this navigation may be one of the following: same record, change record, change data block. See if any of this may be helpful to you.