Core Data Relationships cause save error after delete

This question is probably a long shot. I can't figure out the errors I'm getting on my core data project when I save after I delete an entity.

I have two main entities that I work with, an Outfit, and an Article. I can create them with no problem but when I delete them I get the follow error log:

For the Outfit:

2009-09-22 20:17:37.771 itryiton[29027:20b] Operation could not be completed. (Cocoa error 1600.)
2009-09-22 20:17:37.773 itryiton[29027:20b]   {
    NSLocalizedDescription = "Operation could not be completed. (Cocoa error 1600.)";
    NSValidationErrorKey = outfitArticleViewProperties;
    NSValidationErrorObject = <Article: 0x12aa3c0> (entity: Article; id: 0x12b49a0 <x-coredata://7046DA47-FCE1-4E21-8D7B-E532AAC0CC46/Article/p1> ; data: {
    articleID = 2009-09-22 19:05:19 -0400;
    articleImage = 0x12b4de0 <x-coredata://7046DA47-FCE1-4E21-8D7B-E532AAC0CC46/ArticleImage/p1>;
    articleType = nil;
    attributeTitles = "(...not nil..)";
    color = nil;
    comment = nil;
    dateCreated = 2009-09-22 19:05:19 -0400;
    designer = nil;
    imageView = "(...not nil..)";
    location = "(...not nil..)";
    outfitArticleViewProperties =     (
        0x12b50f0 <x-coredata://7046DA47-FCE1-4E21-8D7B-E532AAC0CC46/OutfitArticleViewProperties/p1>
    );
    ownesOrWants = 0;
    pattern = nil;
    price = nil;
    retailer = nil;
    thumbnail = "(...not nil..)";
    washRequirements = nil;
    wearableSeasons = nil;
});
    NSValidationErrorValue =     {(
        <OutfitArticleViewProperties: 0x1215340> (entity: OutfitArticleViewProperties; id: 0x12b50f0 <x-coredata://7046DA47-FCE1-4E21-8D7B-E532AAC0CC46/OutfitArticleViewProperties/p1> ; data: {
    article = 0x12b49a0 <x-coredata://7046DA47-FCE1-4E21-8D7B-E532AAC0CC46/Article/p1>;
    articleViewPropertiesID = nil;
    outfit = nil;
    touch = nil;
    view = "(...not nil..)";
})
    )};
}

And if I delete an Article