FCKeditor: Invalid argument supplied for foreach()

Ik ben bezig met FCKeditor en op mn localhost (PHP Version 5.1.2) werkt het prima.
Maar upload ik m naar een server met PHP Version 4.4.2 dan krijg ik de foutmelding:
Warning: Invalid argument supplied for foreach() in .... /fckeditor.php on line 110

De code is erg lang van fckeditor.php maar ik zal m posten, hopelijk kan iemand me helpen
want ik snap niet waarom het niet werkt.
De argumenten lijken wel degelijk te kloppen (en werkt dus ook in PHP 5.1.2)

<? class RCMS
{
var $InstanceName ;
var $BasePath ;
var $Width ;
var $Height ;
var $ToolbarSet ;
var $Value ;
var $Config ;

// PHP 5 Constructor
function __construct( $instanceName )
{
$this->InstanceName = $instanceName ;
$this->BasePath = '/FCKeditor/' ;
$this->Width = '100%' ;
$this->Height = '500' ;
$this->ToolbarSet = 'Default' ;
$this->Value = '' ;

$this->Config = array() ;
}

// PHP 4 Contructor
function FCKeditor( $instanceName )
{
$this->__construct( $instanceName ) ;
}

function Create()
{
echo $this->CreateHtml() ;
}

function CreateHtml()
{
$HtmlValue = htmlspecialchars( $this->Value ) ;

$Html = '<div>' ;

if ( $this->IsCompatible() )
{
if ( isset( $_GET['fcksource'] ) && $_GET['fcksource'] == "true" )
$File = 'fckeditor.original.html' ;
else
$File = 'fckeditor.html' ;

$Link = "{$this->BasePath}editor/{$File}?InstanceName={$this->InstanceName}" ;

if ( $this->ToolbarSet != '' )
$Link .= "&amp;Toolbar={$this->ToolbarSet}" ;

// Render the linked hidden field.
$Html .= "<input type=\"hidden\" id=\"{$this->InstanceName}\" name=\"{$this->InstanceName}\" value=\"{$HtmlValue}\" style=\"display:none\" />" ;

// Render the configurations hidden field.
$Html .= "<input type=\"hidden\" id=\"{$this->InstanceName}___Config\" value=\"" . $this->GetConfigFieldString() . "\" style=\"display:none\" />" ;

// Render the editor IFRAME.
$Html .= "<iframe id=\"{$this->InstanceName}___Frame\" src=\"{$Link}\" width=\"{$this->Width}\" height=\"{$this->Height}\" frameborder=\"no\" scrolling=\"no\"></iframe>" ;
}
else
{
if ( strpos( $this->Width, '%' ) === false )
$WidthCSS = $this->Width . 'px' ;
else
$WidthCSS = $this->Width ;

if ( strpos( $this->Height, '%' ) === false )
$HeightCSS = $this->Height . 'px' ;
else
$HeightCSS = $this->Height ;

$Html .= "<textarea name=\"{$this->InstanceName}\" rows=\"4\" cols=\"40\" style=\"width: {$WidthCSS}; height: {$HeightCSS}\">{$HtmlValue}</textarea>" ;
}

$Html .= '</div>' ;

return $Html ;
}

function IsCompatible()
{
global $HTTP_USER_AGENT ;

if ( isset( $HTTP_USER_AGENT ) )
$sAgent = $HTTP_USER_AGENT ;
else
$sAgent = $_SERVER['HTTP_USER_AGENT'] ;

if ( strpos($sAgent, 'MSIE') !== false && strpos($sAgent, 'mac') === false && strpos($sAgent, 'Opera') === false )
{
$iVersion = (float)substr($sAgent, strpos($sAgent, 'MSIE') + 5, 3) ;
return ($iVersion >= 5.5) ;
}
else if ( strpos($sAgent, 'Gecko/') !== false )
{
$iVersion = (int)substr($sAgent, strpos($sAgent, 'Gecko/') + 6, 8) ;
return ($iVersion >= 20030210) ;
}
else
return false ;
}

function GetConfigFieldString()
{
$sParams = '';
$bFirst = true;
//-- HIER GAAT HET MIS -----------------------------------------------------------------
foreach($this->Config as $sKey => $sValue)
{
if ( $bFirst == false )
$sParams .= '&amp;' ;
else
$bFirst = false ;

if ( $sValue === true )
$sParams .= $this->EncodeConfig( $sKey ) . '=true' ;
else if ( $sValue === false )
$sParams .= $this->EncodeConfig( $sKey ) . '=false' ;
else
$sParams .= $this->EncodeConfig( $sKey ) . '=' . $this->EncodeConfig( $sValue ) ;
}

return $sParams ;
}

function EncodeConfig( $valueToEncode )
{
$chars = array(
'&' => '%26',
'=' => '%3D',
'"' => '%22' ) ;

return strtr( $valueToEncode, $chars ) ;
}
}

?>