Blue Screens caused by Vista Calendar

The Vista Windows Calendar was copied to Windows 7 by me.Calendar worked great.But when I try to delete an entry, it causes a Blue Screen.what would cause this. It happened 6 times.
I prefer the Vista Calendar. I am also curious because this never happened in the three months that I ran the Beta, only with the RC.

Windows Vista Calendar application does not run under Windows 7.It's not support.You can use the new calendar function embedded in the Windows Live suite.
Also,you can use Windows desktop gadgets for Calendar or Google calendars.