Drupal 7.22
Template: 

Template id	3
Name	Artikel to Artikel2
Source type	book
Destination type	artikel2
Source fields	taxonomy_vocabulary_6, body, upload, field_artikeldatum
Destination fields	append_to_body, append_to_body, field_artik2anhang, field_artik2beitragsdatum

The following Notice ist logged:
Notice: Undefined index: value in node_convert_field_convert() (Zeile 900 von /home/www/vtad7test/sites/all/modules/node_convert/node_convert.module).

and the taxonomy_vocabulary_6 ist lost (not appended).
The other fields are converted correctly.