This problem may be caused by having multiple NICs (network adapters), or if you have multiple IP addresses assigned to one NIC. As stated in the Installation Guide, if your network card is bound to more than one IP address, the agent uses the first IP address on the network card.
If you look at the first line in the agentinitial.log and the SISIPSService.log on the agent, you will see the IP address being used.
check this link and let know if it helps?
http://www.symantec.com/business/support/index?page=content&id=TECH161364