samba 3 on CURRENT and net.inet.tcp.blackhole

Hello,
I have a problem with samba 3.0.
I had to reinstall FreeBSD-CURRENT after known problems with ATAng and 
atapicam (beginning of September(?)), since then I can't set
net.inet.tcp.blackhole=2 in /etc/sysctl.conf. If I add the option to 
sysctl then
samba will hung until I press ^C. If I boot without this option then samba
starts fine. However running now
sysctl net.inet.tcp.blackhole=2 prevent smbclient from running. I still 
will be
able to connect to smb shere from another computer. It seems that this 
is local
problem but it never occurred before FreeBSD re-instal with samba 3.0. I 
do not
see any errors in log files. I also contacted mantainer of samba but he was
unable to help. I dont think that it is the issue with samba because samba 3
(devel) worked with previous snaps. So there must be something 
particular with
my configuration of FreeBSD

I would appreciate any help

Michal