i changed $image_norm with $image now it's correct for this post, but still larger pictures only thumbnails in black.

imagecopyresampled($image_norm, $image, 0,0, 0,0,200,$hoehe_norm,$breite,$hoehe);

Please provide the original image. Use a simple script without dynamic values, something like the sample available at  http://de3.php.net/imagecopyresampled

--Pierre

ok here we go.

i made a few test with different sizes of pictures.
above 2900 x 1933 pixel the thumbnail is only black.

i use this code for upload the picture:
--------------------------------------------------
###links zum Uploadverzeichnis###
$bildlink = "thumbs" ;

$dateiname = $_FILES['datei']['name'] ;
$dateitype = $_FILES['datei']['type'] ;
$dateisize = $_FILES['datei']['size'] ;

if (empty($dateiname)) {$fehlermeldung = ''.$TEXT['FILENAME'].'' ; }

elseif ( $dateisize > '5240000') {$fehlermeldung = ''.$TEXT['FILESIZE'].'' ; }

elseif ( strlen( $dateiname ) > '25')
{    
$dateinamengroesse = strlen($dateiname) - 25 ;
$fehlermeldung = ''.$TEXT['FILELAENGE'].'' ;
}
    
  elseif ( $dateitype == 'image/jpeg' || $dateitype == 'image/pjpeg' ) {
  
    ## umwandeln von umlauten ##
    $dateiname1 = strtr("$dateiname", " ????", "_aous") ;
    
    ## umwandeln in kleinbuchstaben ##
    $dateiname2 = strtolower("$dateiname1") ;

    $bildteil = split("[.]",$dateiname2) ;
    $dateivorhanden = file_exists($bildlink.'/'.$bildteil[0].'_norm.'.$bildteil[1]) ;

if ($dateivorhanden) {$fehlermeldung = ''.$TEXT['FILEEXIST'].'' ;}

    else {
      ## originalbild uploaden ##
      move_uploaded_file( $datei , $bildlink.'/'.$dateiname2 ) ;

      ## wie gro? ist das originalbild ##
      $gross = getimagesize( $bildlink.'/'.$dateiname2 ) ;
      $breite = $gross[0] ;
      $hoehe = $gross[1] ;
      $typ = $gross[2] ;

      $hoehe_norm = $hoehe * 200 / $breite ;
      $image_norm = imagecreatetruecolor( 200 , $hoehe_norm ) ;

      ## neuen namen f?rs thumbnail vergeben ##
      $bild_s = split("[.]",$dateiname2);
      $dateiname2_norm = $bild_s[0].'_norm.'.$bild_s[1] ;

      ## thumbnail erstellen ##
      $image_norm = imagecreatetruecolor(200, $hoehe_norm);
      $image = imagecreatefromjpeg( $bildlink.'/'.$dateiname2 ) ;
        imagecopyresampled($image_norm, $image, 0,0, 0,0,200,$hoehe_norm,$breite,$hoehe);
      imagejpeg($image_norm, $bildlink.'/'.$dateiname2_norm , 100 );

      $fehlermeldung = ''.$TEXT['FILEDONE'].'' ;
    }
  }
   else {$fehlermeldung = ''.$TEXT['FILEDONEERROR'].'';
  }
} 
-------------------------------------------------

please download example pictures here:

original picture with 3072 pixel:
http://www.klixx.com/picsearch/thumbs/testbild_3072.jpg

example picture with 2600 pixel:
http://www.klixx.com/picsearch/thumbs/testbild_2600.jpg

example picture with 2900 pixel:
http://www.klixx.com/picsearch/thumbs/testbild_2900.jpg

thanks for help

Sorry, but your problem does not imply a bug in PHP itself.  For a
list of more appropriate places to ask for help using PHP, please
visit http://www.php.net/support.php as this bug system is not the
appropriate forum for asking support questions. 

Even if you think it is not a bug, we often know better than you,
please consult the support channels first before even considering
to reopen this report.

Thank you for your interest in PHP.

testbild_2900.jpg is a correct jpeg and imagecopyresamples works with an image created using it. The two others are broken.

--Pierre