UDP packets "dropped due to full socket buffers"

[Dmitry S. Vlasov]

Hello!
I see next one:

server[root]:/var/tmp # netstat -n -a -p udp
Active Internet connections (including servers)
Proto Recv-Q Send-Q  Local Address          Foreign Address        (state)
udp4   33269      0  *.1646                 *.*
udp4       0      0  *.1645                 *.*
udp4       0      0  *.69                   *.*
udp4       0      0  *.514                  *.*


server[root]:/var/tmp # netstat -n -s -a -p udp
udp:
        28698464 datagrams received
        0 with incomplete header
        0 with bad data length field
        0 with bad checksum
        187 with no checksum
        977 dropped due to no socket
        0 broadcast/multicast datagrams dropped due to no socket
        9688498 dropped due to full socket buffers
        0 not for hashed pcb
        19008989 delivered
        18904504 datagrams output


9688498 UDP datagrams was dropped and it's so sad :(
I try to enlarge this sysctl variable:

net.inet.udp.recvspace = 160000

But problem still exist...

Can you help me, what else i've to do?