tsl 3.0.5 sysctl net.ipv6

Hello List,

my tsl 3.0.5 (2.6.19.7-1tr.bai1) writes to the /var/log/messages while
booting the following line:

Aug 11 15:28:20 odilo kernel: process `sysctl' is using deprecated
sysctl (syscall) net.ipv6.neigh.lo.base_reachable_time; Use
net.ipv6.neigh.lo.base_reachable_time_ms instead.

Networking works well.
Is it a grave issue? How to avoid this?

Thanks & Bye,
Florian