ipfw nat 1 config not_good_anymore? (FreeBSD 9.0-RC2)

[H]

somebody else experience problems with ipfw nat?

even the most simple ruleset as

ipfw add nat 1 ip from any to any via em0        
ipfw nat 1 config if em0 reset
ipfw add pass proto ip

is not working anymore, funny is the counter of each rule increase (ipfw show) 
but there is no traffic outgoing on the LAN_IF neither get some to the client 
machine (yeah, the IFs are up and cable is plugged in :)

tcpdump captures 0 (zero) returning traffic on the LAN 

I can access normally from the machine any destiny on either side of it

please don't ask for IPFIREWALL_FORWARD, IPFIREWALL_NAT LIBALIAS and IPDIVERT  
nor sysctls .. unless there is an undocumented change. 

thank's

HM
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