Lionel,

L> I tried with the other tables and it is the same result, all records
L> are updated. :(

I think that the problem is that the subquery is executed once
for each record returned by the parent query, as reported here:

http://sourceforge.net/tracker/index.php?func=detail&aid=479483&group_id=9028&atid=109028

IOW it's a known bug. What's unknown is if and when it will be fixed.
;-)

Ciao
--
Nando Dessena
http://www.flamerobin.org