Server 2008 Likes to restart itself

I have a weird issue here.

I notice about once a week the web server restarts itself. This would be only a minor issue if we were not planning on implementing an IP failover.

I have checked the event logs. I don't see anything that indicates a reason for the restart.

I need some help diagnosing the reason the server restarts. It happened last night at 5:00AM Last even in the log was 1 hour before the unexpected shutdown.

Here is the Log for the shutdown event. Any help is much appreciated. I know there isn't much to go on yet.

    Log Name:      System

Source:        EventLog

Date:          5/5/2010 5:01:12 AM

Event ID:      6008

Task Category: None

Level:         Error

Keywords:      Classic

User:          N/A

Computer:      SERVERNAME

Description:

The previous system shutdown at 4:56:41 AM on 5/5/2010 was unexpected.

Event Xml:

<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">

  <System>

    <Provider Name="EventLog" />

    <EventID Qualifiers="32768">6008</EventID>

    <Level>2</Level>

    <Task>0</Task>

    <Keywords>0x80000000000000</Keywords>

    <TimeCreated SystemTime="2010-05-05T09:01:12.000Z" />

    <EventRecordID>346094</EventRecordID>

    <Channel>System</Channel>

    <Computer>SERVERNAME</Computer>

    <Security />

  </System>

  <EventData>

    <Data>4:56:41 AM</Data>

    <Data>5/5/2010</Data>

    <Data>

    </Data>

    <Data>

    </Data>

    <Data>39594</Data>

    <Data>

    </Data>

    <Data>

    </Data>
    <Binary>DA070500030005000400380029008E03DA070500030005000800380029008E033C0000003C000000000
000000000000000000000000000000100000000000000</Binary>

  </EventData>

</Event>