Ann,
Thank you very much.
One last question before following you advice:
Do you think that those error messages found in the
/var/log/firebird.log are cause or consequence of the "lock manager
out of room" error ? The errors reported are the following (the last
one repeats for ever, as you see):

servin (Server) Fri Feb 23 09:31:43 2007
INET/inet_error: read errno = 9

servin (Server) Fri Feb 23 09:31:43 2007
SCH_validate -- not entered

servin (Server) Fri Feb 23 09:33:43 2007
INET/inet_error: read errno = 88

servin (Server) Fri Feb 23 09:33:43 2007
INET/inet_error: send errno = 88

servin (Server) Fri Feb 23 09:33:43 2007
Database:
I/O error for file "/var/lib/firebird2/data/webhammer.fdb"
Error while trying to write to file
Bad file descriptor

servin (Server) Fri Feb 23 09:33:43 2007
Database:
I/O error for file "/var/lib/firebird2/data/webhammer.fdb"
Error while trying to write to file
Bad file descriptor

servin (Server) Fri Feb 23 09:33:43 2007
Database:
I/O error for file "/var/lib/firebird2/data/webhammer.fdb"
Error while trying to write to file
Bad file descriptor

Aldo