Empty space on top of the page I coded some modules (basically only PHP and no alter of Drupal functions), and on mysterious way, two of my modules are producing an empty quote on top of my meta tags in the body.
This causes a 20 empty pixels on top of my page, and destroys my slider.

As mentioned, two modules are producing this; I figured out that the first module produces this when I use include_once("config/rewards.inc");. If I comment it out, everything works fine. 
include_once("config/rewards.inc"); is already included in one of my other modules, but I used include_once, to include it, obviously, only once.
include_once("config/config.inc"); doesn't produce this error. 

This is a screenshot of Firebug (the arrow point at the margin).



In my first module, the problem happens when I uncomment the line containing require_once("config/rewards.inc").

&lt;?php 
//      *****************************************
//      **      Donate Script for Trinity      **
//      **             by Leandros         **
//      *****************************************


//module_load_include('inc', 'donatescript', 'rewards');
//module_load_include('inc', 'donatescript', 'config');
require_once("config.inc");
//Produce problems (for some reason I dont know ^^)
//require_once("config/rewards.inc");

if(user_is_logged_in()){
global $user;
global $donatepoints;
$userip = $user-&gt;hostname;
$userid = $user-&gt;uid;
$username = $user-&gt;name;
$usernameuc = strtoupper($user-&gt;name);


//$GLOBALS['reward_items'] = $tab_rewards;
//$GLOBALS['reward_texts'] = $reward_texts;

//Get Variables from config.inc for realmd DB
$db = $realmd_DB['1']['3'];
$host = $realmd_DB['1']['0'];
$dbuser = $realmd_DB['1']['1'];
$dbpassword = $realmd_DB['1']['2'];

//Connect to realmd DB
$connect = mysql_connect($host, $dbuser, $dbpassword) or die (mysql_error());
mysql_select_db($db, $connect) or die (mysql_error());

//query overall donatepoint value
$donate_points_select = mysql_query("SELECT points FROM donate_points WHERE id='$userid'");
while($row = mysql_fetch_array($donate_points_select)) {
    $donatepoints = $row['points'];
}

if($donatepoints == 0) {
    $GLOBALS['donatepoints'] = 0;
} else {
    $GLOBALS['donatepoints'] = $donatepoints;
}

//mysql_query("INSERT INTO `donate_points` (`id`, `name`, `points`) VALUES ('$userid', '$usernameuc', '$donatepoints')");

//Close DB connection
mysql_close($connect);
}
?&gt;
I found the error in the second module: It was because the opening &lt;?php tag had a tab before it.

I fixed the second module, too. I don't know which produced the empty space, but I created for every file I used a new file and pasted my code into, renamed the module and enabled it. Everything now works.