UPDATE doesn't work

[PaT!]

Hi 
I'm running MySQL 4.0.13
MS Windows XP Prof
 
I've this problem:
A db with a table called 'ordini' 
 
mysql> desc ordini;
+-------------+---------------+------+-----+------------+---------------
-+
| Field       | Type          | Null | Key | Default    | Extra
|
+-------------+---------------+------+-----+------------+---------------
-+
| id          | int(11)       |      | PRI | NULL       | auto_increment
|
| numordine   | int(10)       |      |     | 0          |
|
| descrizione | varchar(150)  |      |     |            |
|
| marca       | varchar(250)  |      |     |            |
|
| modello     | varchar(250)  |      |     |            |
|
| generica    | varchar(250)  |      |     |            |
|
| quantita    | int(10)       |      |     | 0          |
|
| prezzo      | decimal(10,3) |      |     | 0.000      |
|
| type        | varchar(10)   |      |     |            |
|
| dataord     | date          |      |     | 0000-00-00 |
|
| nominativo  | varchar(200)  |      |     |            |
|
| totale      | decimal(10,3) |      |     | 0.000      |
|
| fromprev    | int(11)       | YES  |     | NULL       |
|
| ptype       | varchar(20)   | YES  |     | NULL       |
|
| idutente    | int(11)       | YES  |     | NULL       |
|
| codcliente  | varchar(8)    | YES  |     | NULL       |
|
| datamod     | date          | YES  |     | NULL       |
|
+-------------+---------------+------+-----+------------+---------------
-+
17 rows in set (0.00 sec)
 
I need to update some values in two fields 'prezzo' and 'totale' These
are the values before the UPDATE
 
mysql> SELECT prezzo, totale FROM ordini WHERE numordine=1157;
+--------+--------+
| prezzo | totale |
+--------+--------+
|  6.795 |  6.795 |
| 13.835 | 13.835 |
| 17.578 | 17.578 |
| 62.500 | 62.500 |
+--------+--------+
4 rows in set (0.02 sec)
 
this is the UPDATE query
 
mysql> UPDATE ordini SET prezzo = prezzo/1.024, totale = totale/1.024
WHERE numordine>1385 AND dataord<'2003-06-01';
Query OK, 1649 rows affected (0.10 sec)
Rows matched: 1650  Changed: 1649  Warnings: 0
 
These are the values after the UPDATE
 
mysql> SELECT prezzo, totale FROM ordini WHERE numordine=1157;
+--------+--------+
| prezzo | totale |
+--------+--------+
|  6.795 |  6.795 |
| 13.835 | 13.835 |
| 17.578 | 17.578 |
| 62.500 | 62.500 |
+--------+--------+
4 rows in set (0.02 sec)
 
Why the values didn't update?
The same query applied on a single row works perfectly.
 
Any help is appreciated
 
PaT!