The ntp-4.1.1b ebuild installs a /etc/ntp.conf file that refers to /var/state/ntp.drift (used to be /etc/ntp.drift). However, it doesn't create /var/state if it isn't already there. Not exactly a big problem, I admit.
*** This bug has been marked as a duplicate of 11352 ***
*** Bug 90607 has been marked as a duplicate of this bug. ***