Hi, I have problems with a Cisco 3845 restarting today,

this is the IOS Version:

Cisco IOS Software, 3800 Software (C3845-IPBASE-M), Version 12.4(3i), RELEASE SOFTWARE (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2007 by Cisco Systems, Inc.
Compiled Thu 29-Nov-07 04:44 by stshen

ROM: System Bootstrap, Version 12.4(13r)T, RELEASE SOFTWARE (fc1)

INTERNET_BABAHOYO uptime is 14 minutes
System returned to ROM by power-on
System image file is "flash:c3845-ipbase-mz.124-3i.bin"

And these are log messages:

*Apr 14 16:32:00: %SYS-6-CLOCKUPDATE: System clock has been updated from 21:32:00 UTC Wed Apr 14 2010 to 16:32:00 GMT Wed Apr 14 2010, configured from console by console.
*Apr 14 16:32:01: %SYS-5-CONFIG_I: Configured from memory by console
*Apr 14 16:32:01: %SYS-5-RESTART: System restarted --
Cisco IOS Software, 3800 Software (C3845-IPBASE-M), Version 12.4(3i), RELEASE SOFTWARE (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2007 by Cisco Systems, Inc.
Compiled Thu 29-Nov-07 04:44 by stshen
*Apr 14 16:32:01: %SNMP-5-COLDSTART: SNMP agent on host INTERNET_BABAHOYO is undergoing a cold start
*Apr 14 16:32:01: %LINEPROTO-5-UPDOWN: Line protocol on Interface Loopback0, changed state to up

This router has two Power Supplies installed : one of them is AC and the other one is DC, however DC power supply is not connected to DC power some months ago and this problem is present since today.

I want to know if messages logged in buffer is because of restarting router or, if the restart is because of some issue which is logging messages in buffer before going to restart.

I know that message "System returned to ROM by power-on" means router restart by power, but i don´t know if this is a generic message that appears by default after restart by any other reason.

I appreciate your opinions and help

Regards.

William