Why do I get a "mysql_query(): supplied argument is not a valid" for the first...

$r = mysql_query($q, $connection);

In the following code...

$bId    = trim($_POST['bId']);
$title  = trim($_POST['title']);
$story  = trim($_POST['story']);

$q  = "SELECT * ";
$q .= "FROM " . DB_NAME . ".`blog` ";
$q .= "WHERE `blog`.`id` = {$bId}";
$r = mysql_query($q, $connection);
//confirm_query($r);
if (mysql_num_rows($r) == 1) {      
    $q  = "UPDATE " . DB_NAME . ".`blog` SET
                        `title` = '{$title}',
                        `story` = '{$story}'
                    WHERE `id` = {$bId}";
    $r = mysql_query($q, $connection);
    if (mysql_affected_rows() == 1) {
        //Successful
        $data['success'] = true;
        $date['errors']  = false;
        $date['message'] = "You are the Greatest!";
    } else {
        //Fail
        $data['success'] = false;
        $data['error']   = true;
        $date['message'] = "You can't do it fool!";
    }        
}

I also get an "mysql_num_rows(): supplied argument is not a valid MySQL result resource" error too.

Side notes: I am using 1&1 Hosting (worst hosting ever), custom .htaccess file with one line text to enable PHP 5.2 (only why with 1&1 Hosting).