Problems with PHP response to flash uploader

Code:
function ddPieceUploaderImage()

    {

        $this->load->model('portfolio/piece_model');

        

        $userid = $this->input->post('Name');

        $folderid = $this->input->post('var1');

        $projectid = $this->input->post('var2');

       

        // set up some stuff for the uploader

        $aCfg = array();

        $aCfg['upload_path']      = '../../folder/media/image/';

        $aCfg['allowed_types'] = 'gif|jpg|jpeg|png';

        $aCfg['max_size']        = '2000';

        $aCfg['encrypt_name']    = TRUE;

        $aCfg['is_flash_upload'] = TRUE; // i do have a flash-upload with application/octet-stream instead of image/jpg

        //echo "4";

        $this->upload->initialize($aCfg);

        //echo "5";   



            

        // filedata is the name of the file-input field / ie. form

        if ( $this->upload->do_upload('Filedata') == FALSE )

        {

            // there is an error when uploading the file

            log_message('error', 'Flas Upload: error uploading the image: '.$this->upload->display_errors());

            echo "error";

        } else {

            $fInfo = $this->upload->data();

            $rawname                 = $fInfo['raw_name']; // name of file without extension

            $data['piecetypeid']     = 1; // 1 = image

            $data['userid']             = $userid; 

            $data['projectid']         = $projectid; 

            $data['position']         = $this->piece_model->getNextPosition($projectid); // get next piece position

            $data['url']             = $rawname;

            $data['title']             = $fInfo['orig_name']; // to do

            $data['datetime']         = time();

            $pieceid                 = $this->piece_model->addPiece($data,$userid); // get next piece position



            $this->_createLargeImage($fInfo['file_name'], $fInfo['raw_name'], $fInfo['file_ext']);

            //80x80 thumb

            $this->_createThumb($fInfo['file_name'], $fInfo['raw_name'], $fInfo['file_ext'],$fInfo['image_width'],$fInfo['image_height'],80);

            //132x132 thumb

            $this->_createThumb($fInfo['file_name'], $fInfo['raw_name'], $fInfo['file_ext'],$fInfo['image_width'],$fInfo['image_height'],132);

            //272x272 thumb

            $this->_createThumb($fInfo['file_name'], $fInfo['raw_name'], $fInfo['file_ext'],$fInfo['image_width'],$fInfo['image_height'],272);

            //406x180 folder thumb

            $this->_createThumb($fInfo['file_name'], $fInfo['raw_name'], $fInfo['file_ext'],$fInfo['image_width'],$fInfo['image_height'],406, TRUE);

            //406x180 rollover thumb

            $this->_makeRollOverThumb($fInfo['file_name'], $fInfo['raw_name'], $fInfo['file_ext'],$fInfo['image_width'],$fInfo['image_height']);            

            echo "varback1=$pieceid&varback2;=$rawname";

        }

    }