[cisco-voip] Device unregistered - Reason code 8

[nenad lazarevic]

I have Callmanager Cluster with 3 CallManager 4.1.3(1 publisher + 2
subscriber) . On Central location I have DHCP server for voice vlan
100 with option 150.  All phones at the central location belong to
CallManager group (subscriber1, subscriber2, publisher) with address
from vlan 100.

In Application log at subscriber1 I have lot of messages. vlan 100.

Event Type:	Error
Event Source:	Cisco CallManager
Event Category:	None
Event ID:	3
Date:		11/20/2007
Time:		11:20:48 AM
User:		N/A
Computer:	SUBSCRIBER1
Description:
Error: DeviceUnregistered - Device unregistered.
  Device name.: SEP004C58A2CEA2
  Device IP address.: 10.56.100.56
  Device type. [Optional]: 307
  Device description [Optional]
  Reason Code [Optional].: 8
  App ID: Cisco CallManager
  Cluster ID: CCMCLUSTER
  Node ID: 10.67.23.24
Explanation: A device that has previously registered with Cisco
CallManager has unregistered. This event may be issued as part of
normal unregistration event or due to some other reason such as loss
of keepalives.
Recommended Action: No action is required if unregistration of this
device was expected..

90% of messages is for phones from Central location with address from
vlan  100. What is the reason for this error?DHCP lease? I dont have
complainnig from users. but log is full of error messages?

TXH