kern/141843: [em] [vlan] Intel txcsum and assigned vlan invoke wrong dst MAC in TCP packets

[Prokofiev S.P.]

Thanks Pyun YongHyeon!
I apply patch em.csum_tso.20091230.patch and rebuild/reinstall kernel 
and have received successful result for tcp and udp connections (test by 
iperf).
But the  hangs down/up nic bug do not disappear (kern/141285 without 
connection problems after your patch). Please pay attention to this problem.