admin view field not displaying in list view

[kmd-muc]

Hi,
I have a very simple admin view with only 2 fields, one text field and one custom dropdown that pulls its entries from a database table.
I have set both fields to "show in all list views" but the custom field's values are not displayed. So I took a closer look to the default_body.php file and there I found the reason:
Instead of
<?php echo $this->escape($item->zu_fzmodell_marke); ?>
it says:
<?php echo $this->escape($item->zu_fzmodell_marke_zu_fzmodell_marke); ?>
So it inserts the field's name twice.
Strange thing is: I have two versions of this field: the only difference (besides type and name) is, one has multiple set to true and the other one has it set to false.
So this doesn't happen, when multiple is set to true.
Did I miss anything, or is this just a bug?