function flexinode_field_file_insert($field, $node) {

$fieldname = 'flexinode_'. $field->field_id;
$node->$fieldname = file_save_upload($node->$fieldname, $node->$fieldname->filename);

$serialized = is_object($node->$fieldname) ? serialize($node->$fieldname) ;

There is a problem here. If we include the same file (name) in two different file fields, it doesnt work. only one of them is loaded.

There is a related bug, if the filename already exists in files directory then you cant upload it again using flexinode.

-v