uc_importer&field_image_cache

I use uc_importer - in input XML file present block but this image not write to product - why?
I see uc_importer.module and not found where write data in tables (files,content_field_image_cache...).
Module only write my file from XML to patch '/files/'

Help?

P.S. I found error or not?
function uc_importer_import($xml)
... not work (array!=string)
if (!isset($product_data->unique_hash)) {
$product_data->addChild('unique_hash',...

... work
if (!isset($product_data->unique_hash)) {
$product_data->addChild('unique_hash', false, $product_data->level() + 1);
$unique_hash = md5(...);
$product_data->unique_hash[0]->setData($unique_hash);