Hotmail, the Windows Phone website, even Bing. I check the "keep me logged in" box, and yet every time I go to do anything, I have to sign in. It's super annoying.
Windows live has never seemed real friendly to mobile devices in general.
I mean the websites, from my computer. Like if you go to Windows Phone | Cell Phones, Mobile Downloads, Mobile Apps, and More | Windows Phone 7, every single time I go there I have to log in.
Yes, Windows Live often doesn't honor the keep me logged in settings. Maybe it's a cookie issue?