ping: sendmsg: No buffer space available

when I conect to network using my build in wifi in my netbook (bcm4312(rev 1)), after a few minutes, ping result this error mesg 
      ping: sendmsg: No buffer space available

and the problem gone by typing this (as root), 
      echo 83886080 > /proc/sys/net/core/wmem_max

     ulimits -s 10240