Does anyone else have this problem? Changed over to winter KS duvet (for double bed to give extra coverage) but the top corners of the duvet refuse to stay in the top corners of the duvet cover despite my shaking it several times. So now most of the duvet (and its warmth) is in the bottom half of the cover. At least it has warmed me up but also made me very cross. (Disclaimer - monthly visitor due next weekend). Does anyone have any ideas how to resolve this?