Problem with PDO Mysql and FETCH::ASSOC

Hello,

I am using the following code to perform queries on a MySQL database:

$dbh = new PDO($GLOBALS['database'],$GLOBALS['username'], 
$GLOBALS['password']);
$dbh->setAttribute(PDO::ATTR_EMULATE_PREPARES, true);
$dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$query = $dbh->prepare("SELECT * FROM log");
$query->execute();
$results = $query->fetchALL(PDO::FETCH_ASSOC);
$dbh = null;

If I perform this query in MySQL, I get:

mysql> select * from log;
+---------+------------+-------------------------------+---------- 
+----------------+----------------------------+
| type    | date       | client_id                     | model_id |  
request        | message                    |
+---------+------------+-------------------------------+---------- 
+----------------+----------------------------+
| message | 1.2375e+09 | domain.18052                  |          |  
client_start   | started client             |

However, if I perform this query with the PHP code above, I get:

Array ( [type] => error [date] => 1.2375e+09 [log] => [distributed] =>  
client_start [def] => started client) )

which is clearly wrong. 'distributed' is actually the name of the  
database, so I don't really know what it is doing as a key in the  
above result.

If I use PDO::FETCH_BOTH instead of PDO::FETCH_ASSOC, I get

Array ( [type] => message [0] => message [date] => 1.2375e+09 [1] =>  
1.2375e+09 [log] => [2] => domain.18052 [3] => [distributed] =>  
client_start [4] => client_start [def] => started client [5] =>  
started client )

which *does* contain the correct values with the numerical keys.  
Before using MySQL, I was using SQLite, and this problem did not occur.

The description of the table is:

mysql> describe log;
+-----------+----------+------+-----+---------+-------+
| Field     | Type     | Null | Key | Default | Extra |
+-----------+----------+------+-----+---------+-------+
| type      | char(10) | YES  |     | NULL    |       |
| date      | float    | YES  |     | NULL    |       |
| client_id | char(50) | YES  |     | NULL    |       |
| model_id  | char(50) | YES  |     | NULL    |       |
| request   | char(20) | YES  |     | NULL    |       |
| message   | char(50) | YES  |     | NULL    |       |
+-----------+----------+------+-----+---------+-------+
6 rows in set (0.00 sec)

Does anyone have any ideas as to what I might be doing wrong?

Thanks for any help!

Thomas