Replication database on slave is not updated

[Mike]

Hello,

We are using mysql v4.0.24 on Linux machines.
I'm trying to set up replication with a master and only one slave
database.
The syncronization seems to work well, the relay file on slave is wrote
correctly (Read_Master_Log_Pos and Relay_Log_Pos are updated) but the
information on slave database is not updated.
Master and slave are sincronyzed as shown below but for some reason I
don't understand.
I have to say thay sometimes the replication worked but sometimes
setting up a new slave or changing a slave to master it does not.

This is what I see on the error.log file

050718 11:23:04 Slave I/O thread killed while reading event
050718 11:23:04 Slave I/O thread exiting, read up to log
'mysql-bin.027', position 382
050718 11:23:04 Error reading relay log event: slave SQL thread was
killed
050718 11:23:07 Slave SQL thread initialized, starting replication in
log 'mysql-bin.027' at position 382, relay log
'/var/log/mysql/relay.001' position: 462
050718 11:23:07 Slave I/O thread: connected to master
'r********@192.168.0.100:3306', replication started in log
'mysql-bin.027' at position 382
This is the master status:

mysql> show master status\G
*************************** 1. row ***************************
File: mysql-bin.027
Position: 382
Binlog_do_db:
Binlog_ignore_db:
1 row in set (0.00 sec)
This is the slave status:

mysql> show slave status\G
*************************** 1. row ***************************
Master_Host: 192.168.0.100
Master_User: replicant
Master_Port: 3306
Connect_retry: 60
Master_Log_File: mysql-bin.027
Read_Master_Log_Pos: 382
Relay_Log_File: relay.001
Relay_Log_Pos: 462
Relay_Master_Log_File: mysql-bin.027
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_do_db: copiare
Replicate_ignore_db:
Last_errno: 0
Last_error:
Skip_counter: 0
Exec_master_log_pos: 382
Relay_log_space: 462
1 row in set (0.00 sec)

This is the processlist:

mysql> show processlist\G
....
*************************** 3. row ***************************
Id: 21
User: system user
Host:
db: NULL
Command: Connect
Time: 1265
State: Waiting for master to send event
Info: NULL
*************************** 4. row ***************************
Id: 22
User: system user
Host:
db: NULL
Command: Connect
Time: 367
State: Has read all relay log; waiting for the I/O slave thread to
update it
Info: NULL
Thank you in advance.

Michele