This is still a bug, but it's not in sysvinit. Renaming S31umountnfs to K31umountnfs might help not because S31umountnfs is called with "start" (everything is called with "stop" for rc0.d and rc6.d), but because it simply happens earlier in the shutdown sequence.
This is most probably a problem with the NetworkManager shutdown timing. This is discussed in bug 211631.
This is still a bug, but it's not in sysvinit. Renaming S31umountnfs to K31umountnfs might help not because S31umountnfs is called with "start" (everything is called with "stop" for rc0.d and rc6.d), but because it simply happens earlier in the shutdown sequence.
This is most probably a problem with the NetworkManager shutdown timing. This is discussed in bug 211631.