ICMP lost every 31 sec

My be you can help me else?

In  the current of several days i have this problem; One of us servers lost icpm packets. And it occurs every day - several times. I logon on this server and look, that ping is lost  when there is such message:

Denial of Service is logger

loss of packages proceeds exactly 31 second

If i disabled Symantec on client in time i have lost packet - icmp at once is ok