Random kernel update breakage

[JB]

JB <jb.1234abcd <at> gmail.com> writes:

> ...
Additional info.

$ cat /usr/lib/pm-utils/sleep.d/01grub
...
# Ensure grub will load the correct kernel on resume from hibernate,
...
        echo "savedefault --default=${current} --once" | \
                /sbin/grub --device-map=/boot/grub/device.map \
                --batch --no-floppy --no-curses >/dev/null
...

Let's see more.
# grub
grub> help savedefault
help savedefault
savedefault: savedefault [--stage2=STAGE2_FILE] [--default=DEFAULT] [--once]
    Save DEFAULT as the default boot entry in STAGE2_FILE. If
    '--once' is specified, the default is reset after the next reboot.
grub> quit

So, savedefault modifies stage2 file.
Could this be a source of grub random instability (grub trashing) ?
JB