Gratisprodukt -> keine zahlungsart

hallo,
versuche grade bei einem gratisprodukt keine bezahlarten anzeigen zu lassen.
gibt es da einen einfachen weg?
hab mal mit bezahlart “gratis” bei einem warenkorb wert von 0 rumprobiert. zeigt er auch an. aber beim submitten kommt dann -3 Bitte wählen Sie ggf. eine andere Zahlungsart.

oxpayment.php… die stelle wo es hakt.
[

]oxDeliverySetList::getInstance()
                            ->getDeliverySetList(
                                        $oUser,
                                        $oUser->getActiveCountry()
                                ));

ergibt:

(
    [oxidstandard] => oxDeliverySet Object
        (
            [_sCoreTbl:protected] => oxdeliveryset
            [_sClassName:protected] => oxdeliveryset
            [_iLanguage:protected] => 0
            [_blEmployMultilanguage:protected] => 1
            [_sOXID:protected] => oxidstandard
            [_iShopId:protected] => oxbaseshop
            [_blIsSimplyClonable:protected] => 1
            [_aErrors:protected] => Array
                (
                )

            [_sCoreTable:protected] => oxdeliveryset
            [_sViewTable:protected] => oxdeliveryset
            [_aFieldNames:protected] => Array
                (
                    [oxid] => 0
                    [oxshopid] => 0
                    [oxactive] => 0
                    [oxactivefrom] => 0
                    [oxactiveto] => 0
                    [oxtitle] => 1
                    [oxpos] => 0
                    [oxtitle_1] => 0
                    [oxtitle_2] => 0
                    [oxtitle_3] => 0
                )

            [_blIsNewCache:protected] => 
            [_sCacheKey:protected] => allviews_i18n
            [_blUseLazyLoading:protected] => 
            [_aSkipSaveFields:protected] => Array
                (
                )

            [_sExistKey:protected] => oxid
            [_blIsDerived:protected] => 
            [_blIsSeoObject:protected] => 
            [_blReadOnly:protected] => 
            [_blIsInList:protected] => 1
            [_isLoaded:protected] => 
            [oxdeliveryset__oxid] => oxField Object
                (
                    [value] => oxidstandard
                )

            [oxdeliveryset__oxshopid] => oxField Object
                (
                    [rawValue] => oxbaseshop
                )

            [oxdeliveryset__oxactive] => oxField Object
                (
                    [rawValue] => 1
                )

            [oxdeliveryset__oxactivefrom] => oxField Object
                (
                    [rawValue] => 0000-00-00 00:00:00
                )

            [oxdeliveryset__oxactiveto] => oxField Object
                (
                    [rawValue] => 0000-00-00 00:00:00
                )

            [oxdeliveryset__oxtitle] => oxField Object
                (
                    [rawValue] => Standardversand
                )

            [oxdeliveryset__oxpos] => oxField Object
                (
                    [rawValue] => 1
                )

            [oxdeliveryset__oxtitle_1] => oxField Object
                (
                    [rawValue] => Standard
                )

            [oxdeliveryset__oxtitle_2] => oxField Object
                (
                    [rawValue] => 
                )

            [oxdeliveryset__oxtitle_3] => oxField Object
                (
                    [rawValue] => 
                )

        )

)