iptables PREROUTING -j LOG

Linux k 2.4.3, debian woody, iptables v1.1.2

A port mapped statically from ppp0 to a computer on the inside (eth0)

iptables -t nat -A PREROUTING -p tcp -i ppp0 --dport 1234 -j DNAT --to-destination 10.1.1.200:4321

This works great.. Now, how can I log these connections?
I would have thought that something like

iptables -A FORWARD -i ppp0 -p tcp --dport 1234 -j LOG

should have done it, but I guess PREROUTING grabs the packet before it
even enters the rest of the chain,I tried with INPUT and changed the fw-
script positions to see if putting it in a different location in the
chain would help, but nothing I tried seemed to work...

any clue? (-j LOG is not valid in the -t nat table)