NAT issue - Packets from Internet to private IP?

[StandaK]

Hi, I use Kerio WinRoute firewall to protect my computer. I am in my ISP's network (using private IPs, I have 172.16.3.30) and I connect to Internet trough ISP's router.

But how is it possible that yesterday in security log in WR this info appeared (briefed):

...detected packet without entry in NAT table...ip+port: 193.69.56.5:666 -> 172.16.3.30:40000...

How is it possible? How can someone connect to me? I thougt private IPs were not routed in Internet so how could this packet with destination IP 172.16.3.30 get to my computer???

Thanks.

Standa.