Lately (last week or so,) when I boot my machine (Debian Testing,) after either a poweroff (via shutdown -h) or reboot (via shutdown -r,) it consistently complains that the root filesystem was not cleanly unmounted, and insists on fscking that filesystem. After the reboot forced by fsck, the machine starts up just fine.
Browsing the init scripts in /etc/rc0.d/ and /etc/rc6.d/, I can't find any sign of anything attempting to unmount the root filesystem. Does anyone have any ideas where this should be happening, please?