[Openswan Users] My ipsec0 device drops nat-t packets

[Ivan Lopez]

Hi people:
I'm new to the list. I've googled a lot but I wasn´t be able to find the answer to my problem.
I've followed Jacco's tutorial to configure IPSEC/L2TP
http://www.jacco2.dds.nl/networking/freeswan-l2tp.html#FreeSWANconfig
It worked fine for not NAT-Ted connections but now I want:

PC(w2k)--------NAT---------OPENSWAN/L2TPD--------INSIDENET

Then, I applied the changes Jacco says in the respective section.
In that scenario, IPSEC connection stablished perfectly but then ipsec0 device starts to drops packets (I can see it with ifconfig)

I'm going to give you my configs if you want but I'm thinking may be someone already had this problem before and could give me any hints. 
I'm using an openswan 2.3.0-2 (from Debian) and (natt patched) 2.4.28 kernel. Patchs applied cleanly.

Best Regards.
Ivan