Lightbox gives _imagefield_file_load() error

Using latest 6.x-1.x-dev version I get an error about PHP can't call "_imagefield_file_load()".

This issue is caused by line 60 in lightbox2.formatter.inc, it must be changed from

$file = _imagefield_file_load($item['fid']);
to
$file = field_file_load($item['fid']);

since imagefield seems to don't provide this file loading method.

Regards