/etc/init.d/procps.sh comes too early in the boot process to apply a lot of sysctl's. As it runs before networking modules are loaded and filesystems are mounted, there are quite a lot of commonly-used sysctl's which are simply ignored on boot and produce errors to the console.
All documentation on the net referring to changing certain settings in /etc/sysctl.conf such as
net.ipv4.netfilter.ip_conntrack_max is wrong for Ubuntu & Debian.
Finally, "It seems to me it is a Debian Squeeze bug, see here for an example and workaround:
In the latter case, the procps init script should take care of loading
them during boot. However, on Squeeze it does not, and you need to
restart it from /etc/rc.local (or similar):
# Load kernel variables from /etc/sysctl.d