PHP & MySQL: variable emptying when put inside mysql_query() [closed]

I've been having an awful problem all day today...

I have to simply insert a row in the database, and I have tested all variables individually. They all work fine but, as soon as I assemble the query and pass the string as a parameter, a particular variable becomes empty.

echo $command = "INSERT INTO rt_hotran (rte_id, htr_seats, htr_notes) VALUES ('9', '".$array[11]."', '".SQLDate($array[13])."')";
$query = mysql_query($command) or die(mysql_error());
die(mysql_info($query));

The echo outputs correctly: INSERT INTO rt_hotran (rte_id, htr_seats, htr_notes) VALUES ('9', '118', '2012-08-06').

The script does not die, but this error comes up on the mysql_info: Warning: mysql_info() expects parameter 1 to be resource, boolean given.

The SQLDate function simply converts a date from d-m-Y to Y-m-d. What could be the problem? The column type is date in MySQL, but I have also already tried setting it to varchar, but it just writes blank... Could anyone please help me find what's wrong?

Also, $array[11] writes fine, but $array[13] does not. The array has 26 values.

function SQLDate($date)
{
    $split = explode("-", $date);
    return $split[2]."-".$split[1]."-".$split[0]; 
}


Array
(
    [0] => AZU
    [1] => AZUL Linhas Aéreas Brasileiras S/A
    [2] => 4000
    [3] => E190
    [4] => 2
    [5] => 3
    [6] => 4
    [7] => 5
    [8] => 6
    [9] => S
    [10] => 
    [11] => 118
    [12] => AZU-000265-006
    [13] => 13-06-2011
    [14] => 14-08-2012
    [15] => 04-09-2012
    [16] => Nacional
    [17] => 1
    [18] => SBJV
    [19] => Lauro Carneiro de Loyola
    [20] => SBKP
    [21] => Viracopos
    [22] => 06:10
    [23] => 07:22
    [24] => 
    [25] => DATA DE VIGÊNCIA: 04/SET/2012
    [26] => 
)

I actually believe that the problem is with the array, as this works:

$array[13] = "13-06-2011";
echo $command = "INSERT INTO rt_hotran (rte_id, htr_seats, htr_notes) VALUES ('9', '".$array[11]."', '".SQLDate($array[13])."')";
$query = mysql_query($command) or die(mysql_error());