Yup, if she tosses you a bone, take it, if she throws garbage, just let it go. This is her negative feelings taking her over.
If she can dig up something nice to say, I would bet on it being sincere, but most of the time you are gonna get her bad mood.
Think of it like childbirth. There's some joke that goes around saying never take anything your wife says to you during labour as intentional or personal - they are in a LOT of PAIN.
I have never had the pleasure of this, but I have seen enough movies with women cursing a blue streak at their husband, threatening to castrate him etc during labour...most of its likley just TV myth, but I think it will help you understand why you just need to ignore her BS.
