Restkit mapping errors

Product and attachments mapping

2012-12-23 13:05:32.567 RCGroup[2109:1ad03] T restkit.object_mapping:RKObjectMappingOperation.m:656 Performing mapping operation: RKObjectMappingOperation for 'Attachment' object. Mapping values from object {
    attachment =     (
                {
            icon = "http://www.website.com/download/1.gif";
            id = 1;
            level = 1;
            "product_id" = 2;
            title = "Scheda Tecnica";
            type = pdf;
            url = "http://www.website.com/download/1.pdf";
        },
                {
            icon = "http://www.website.com/download/2.gif";
            id = 2;
            level = 1;
            "product_id" = 2;
            title = "Scheda Commerciale";
            type = pdf;
            url = "http://www.website.com/download/2.pdf";
        }
    );
} to object <Attachment: 0xa2e01b0> (entity: Attachment; id: 0xa2e01f0 <x-coredata:///Attachment/t2A94551B-0337-42DA-BE90-AB6FA58B5AE92> ; data: {
    code = 0;
    icon = nil;
    level = 0;
    product = nil;
    "product_id" = 0;
    title = nil;
    type = nil;
    url = nil;
}) with object mapping <RKManagedObjectMapping:0x95cb840 objectClass=Attachment keyPath mappings => (
    "RKObjectKeyPathMapping: id => code",
    "RKObjectKeyPathMapping: product_id => product_id",
    "RKObjectKeyPathMapping: type => type",
    "RKObjectKeyPathMapping: level => level",
    "RKObjectKeyPathMapping: title => title",
    "RKObjectKeyPathMapping: icon => icon",
    "RKObjectKeyPathMapping: product => product"
)>
2012-12-23 13:05:32.570 RCGroup[2109:1ad03] T restkit.object_mapping:RKObjectMappingOperation.m:412 Did not find mappable attribute value keyPath 'id'
2012-12-23 13:05:32.571 RCGroup[2109:1ad03] T restkit.object_mapping:RKObjectMappingOperation.m:412 Did not find mappable attribute value keyPath 'product_id'
2012-12-23 13:05:32.571 RCGroup[2109:1ad03] T restkit.object_mapping:RKObjectMappingOperation.m:412 Did not find mappable attribute value keyPath 'type'
2012-12-23 13:05:32.571 RCGroup[2109:1ad03] T restkit.object_mapping:RKObjectMappingOperation.m:412 Did not find mappable attribute value keyPath 'level'
2012-12-23 13:05:32.571 RCGroup[2109:1ad03] T restkit.object_mapping:RKObjectMappingOperation.m:412 Did not find mappable attribute value keyPath 'title'
2012-12-23 13:05:32.571 RCGroup[2109:1ad03] T restkit.object_mapping:RKObjectMappingOperation.m:412 Did not find mappable attribute value keyPath 'icon'
2012-12-23 13:05:32.572 RCGroup[2109:1ad03] D restkit.object_mapping:RKObjectMappingOperation.m:483 Did not find mappable relationship value keyPath 'product'
2012-12-23 13:05:32.573 RCGroup[2109:1ad03] D restkit.object_mapping:RKObjectMappingOperation.m:676 Mapping operation did not find any mappable content
2012-12-23 13:05:32.573 RCGroup[2109:1ad03] W restkit.object_mapping:RKObjectMappingOperation.m:456 WARNING: Failed mapping nested object: (null)
2012-12-23 13:05:32.573 RCGroup[2109:1ad03] T restkit.object_mapping:RKObjectMappingOperation.m:164 Found transformable value at keyPath 'attachments'. Transforming from type '__NSArrayM' to 'NSSet'
2012-12-23 13:05:32.574 RCGroup[2109:1ad03] T restkit.object_mapping:RKObjectMappingOperation.m:572 Found a managedObject collection. About to apply value via mutable[Set|Array]ValueForKey
2012-12-23 13:05:32.574 RCGroup[2109:1ad03] T restkit.object_mapping:RKObjectMappingOperation.m:574 Mapped NSSet relationship object from keyPath 'attachments' to 'attachments'. Value: {(
    <Attachment: 0xa2e01b0> (entity: Attachment; id: 0xa2e01f0 <x-coredata:///Attachment/t2A94551B-0337-42DA-BE90-AB6FA58B5AE92> ; data: {
    code = 0;
    icon = nil;
    level = 0;
    product = nil;
    "product_id" = 0;
    title = nil;
    type = nil;
    url = nil;
})
)}
2012-12-23 13:05:32.575 RCGroup[2109:1ad03] D restkit.object_mapping:RKObjectMappingOperation.m:483 Did not find mappable relationship value keyPath 'category'
2012-12-23 13:05:32.576 RCGroup[2109:1ad03] D restkit.object_mapping:RKObjectMappingOperation.m:662 Finished mapping operation successfully...
2012-12-23 13:05:32.576 RCGroup[2109:1ad03] T restkit.object_mapping:RKObjectMapper.m:293 Examining keyPath 'category' for mappable content...
2012-12-23 13:05:32.576 RCGroup[2109:1ad03] D restkit.object_mapping:RKObjectMapper.m:303 Found unmappable value at keyPath: category
2012-12-23 13:05:32.576 RCGroup[2109:1ad03] D restkit.object_mapping:RKObjectMapper.m:367 The following operations are in the queue: (
    "<NSBlockOperation: 0x95dcfe0>",
    "<NSBlockOperation: 0xa2e1eb0>"
)
2012-12-23 13:05:32.577 RCGroup[2109:1ad03] I restkit.core_data:RKInMemoryManagedObjectCache.m:50 Caching instances of Entity 'Category' by primary key attribute 'code'
2012-12-23 13:05:32.578 RCGroup[2109:1ad03] D restkit.object_mapping:RKObjectMapper.m:382 Finished performing object mapping. Results: {
    product = "<Product: 0xa2d9710> (entity: Product; id: 0xa2d82d0 <x-coredata://3316FF57-6517-4E90-AD3F-7AC5B079936E/Product/p1> ; data: {\n    attachments =     (\n    );\n    category = \"0x95e0af0 <x-coredata://3316FF57-6517-4E90-AD3F-7AC5B079936E/Category/p1>\";\n    \"category_id\" = 1;\n    code = 2;\n    \"full_description\" = \"I condizionatori HEAT HUNTER con mandata dell\\U2019aria a dislocamento, sono la soluzione all\\U2019avanguardia per il condizionamento dell\\U2019aria di centrali telefoniche, internet hotels e locali ad alta concentr\";\n    \"product_name\" = \"NEXT DX......R410A.....Plug fan.....6,3\\U00f7 96,1 kW\";\n    \"short_description\" = \"Condizionatori d\\U2019aria di precisione ad armadio, con mandata aria verso l\\U2019alto o verso il basso, ad espansione diretta per abbinamento a condensatore ad aria remoto.\";\n    \"tech_notes\" = \"\\U2022 Basamento e struttura con telaio in profilati di alluminio verniciati a forno con polveri epossidiche, pannellatura in lamiera zincata a caldo e rivestita esternamente da film in PVC.\\n\\t\\U2022 Ventilatori\";\n})";
}
2012-12-23 13:05:33.278 RCGroup[2109:19d03] Loaded statuses: (
    "<Product: 0x95e7710> (entity: Product; id: 0xa2d82d0 <x-coredata://3316FF57-6517-4E90-AD3F-7AC5B079936E/Product/p1> ; data: <fault>)"
)