I'm leaving your post in the Firewall topic, though I am quite certain that the problem is not with OneCare, but with the Skype software. Without knowing the specifics of the blue screen "stop" error, I can only speculate that buggy driver software caused your PC to crash. This can be due to hardware issues, too, but is most likely something with the Skype software. If you believe it to be due to OneCare, you can contact OneCare support for investigation and help.
How to reach support (FAQ) - http://forums.microsoft.com/WindowsOneCare/ShowPost.aspx?PostID=2421771&SiteID=2
-steve