friend was organising a night in at her house - billed as get together, a few drinks, nibbles and a laugh. Date was in diaries several weeks in advance. 2 days before the event, she sent out an email saying "I have decided to de-invite you" - on the basis that she was behind with her house work and didn't have time to go and buy the drinks/snacks etc.
Not sure whether to admire her for saying she couldn't be bothered, or whether to be cross because we were taking the wine and all she had to provide was a few nibbles. As far as I know (3 weeks later) there were no mitigating circumstances.