I am trying to use do the most simple update query but Doctrine issues an INSERT statement instead of an UPDATE.

    $q = Doctrine_Query::create()
        ->from('Image i')
        ->where('id = ?');

    $image = $q->fetchOne($articleId, Doctrine_Core::HYDRATE_RECORD);
    $image->copyright = "some text";
    $image->save();

I have also tried using the example from the manual, but still a new record gets inserted:

$userTable = Doctrine_Core::getTable('User');

$user = $userTable->find(2);

if ($user !== false) {
    $user->username = 'Jack Daniels';
    $user->save();
}

edit:

This example from the manual works:

$user = new User();
$user->assignIdentifier(1);
$user->username = 'jwage';
$user->save();

The funny thing is that I use this on another model and there it works OK. Maybe I have to fetch the whole array graph for this to work (I have another model in a one to many relationship)?