NIC teaming with VLANs does't work

[Giulio Ferro]

Freebsd 7.2 amd64 recently updated.

I want to aggregate the two nics on my server (em0 and em1) in a single
fec interface (so if one nick / switch is down, the other takes over).
On this interface  I want to build vlans.

Here is the networking section of my /etc/rc.conf:

------------------------------------------------------------------------------
fec_interfaces="fec0"
fecconfig_fec0="em0 em1"
ifconfig_fec0="inet 192.168.28.24 netmask 255.255.255.0"

cloned_interfaces="vlan30 vlan40 vlan50"
ifconfig_vlan30="inet 192.168.30.10 netmask 255.255.255 vlan 30 vlandev 
fec0"
ifconfig_vlan30_alias0="inet 192.168.30.11 netmask 255.255.255.255"
ifconfig_vlan30_alias1="inet 192.168.30.12 netmask 255.255.255.255"
ifconfig_vlan30_alias2="inet 192.168.30.13 netmask 255.255.255.255"
ifconfig_vlan40="inet 192.168.40.10 netmask 255.255.255.0 vlan 40 
vlandev fec0"
ifconfig_vlan50="inet 192.168.50.10 netmask 255.255.255.0 vlan 50 
vlandev fec0"

------------------------------------------------------------------------------

When I launch this configuration the vlans are created correctly and I 
see them as active.
But when I try to ping other hosts in those vlans, the connection 
doesn't succeed.

This is what happens in details:
1) The box is able to arp-request the IPs  of other hosts on the chosen 
vlan (es. vlan40)
2) The IP packets from other hosts show up correctly on vlan40 (seen 
with tcpdump)
3) The box doesn't seem to be able to send IP packets to other hosts, 
even though I can
see them leaving from vlan40 on my host (with tcpdump)

I've tried with bce nics with the same result.

Any help is appreciated. I'm available for tests, patches, and so on...