iptables TARPIT

[Gareth John <gdjohn@egregious.org.uk>]

I am having trouble making a TARPIT rule with iptables.  I am using a 
fresh sarge (testing) install and have tried with both a 2.4 and 2.6 
kernel.  Whe I try to make a rule target TARPIT, I get this:

gw:~# iptables -A INPUT --protocol tcp -j TARPIT
iptables: No chain/target/match by that name

I have tried specifying TARPIT as a match, e.g.

gw:~# iptables -A INPUT --protocol tcp -m TARPIT -j TARPIT
iptables v1.2.9: Couldn't load match `TARPIT'

with similar results.  It is clear that the TARPIT .so is really there:

gw:~# ls -l /lib/iptables | grep TARPIT
-rw-r--r--  1 root root 2104 2004-06-16 01:46 libipt_TARPIT.so

Do I need to do something else to load this library or am I missing 
something obvious?

Thanks,
Gareth