IPv4 static IP address spontaneously cleared out on Windows Server 2008 R2

Question

I believe this question is more appropriate to superuser.com, but possibly it belongs on serverfault.com.

I have a system running Windows Server 2008 R2 and its IPv4 TCP settings are set to a static IP address. Last night, it spontaneously lost network connectivity, and upon examination, all the settings got cleared out (IP address, subnet, and gateway).

I am the only person with administrator access to the machine, and I did not happen to access it in the last few days.

Obviously, a virus is always a kneejerk possibility, but I'm quite confident the system is clean. Does anyone have any (other) idea how this could possibly have happened? Or at the least, anywhere I can look to perhaps shed some more light on the problem?

Some further details from the EventLog:

At 10:27:55 PM:

Installation Ready: The following updates are downloaded and ready for installation. This computer is currently scheduled to install these updates on ‎Thursday, ‎August ‎11, ‎2011 at 3:00 AM: 
- Security Update for Microsoft .NET Framework 4 on Windows XP, Windows Server 2003, Windows Vista, Windows 7, Windows Server 2008, Windows Server 2008 R2 for x64-based Systems (KB2539636)
- Cumulative Security Update for Internet Explorer 8 for Windows Server 2008 R2 x64 Edition (KB2559049)
- Security Update for Microsoft .NET Framework 4 on Windows XP, Windows Server 2003, Windows Vista, Windows 7, Windows Server 2008, Windows Server 2008 R2 for x64-based Systems (KB2487367)
- Security Update for Windows Server 2008 R2 x64 Edition (KB2567680)
- Security Update for Windows Server 2008 R2 x64 Edition (KB2563894)
- Security Update for Windows Server 2008 R2 x64 Edition (KB2536276)
- Update Rollup for ActiveX Killbits for Windows Server 2008 R2 x64 Edition (KB2562937)
- Windows Malicious Software Removal Tool x64 - August 2011 (KB890830)
- Security Update for Microsoft .NET Framework 3.5.1 on Windows 7 and Windows Server 2008 R2 SP1 for x64-based Systems (KB2539635)
- Security Update f

At 3:02:44 AM

Installation Successful: Windows successfully installed the following update: Security Update for Microsoft .NET Framework 4 on Windows XP, Windows Server 2003, Windows Vista, Windows 7, Windows Server 2008, Windows Server 2008 R2 for x64-based Systems (KB2539636)

At 3:06:54 AM

Restart Required: To complete the installation of the following updates, the computer will be restarted within 15 minutes: 
- Security Update for Microsoft .NET Framework 4 on Windows XP, Windows Server 2003, Windows Vista, Windows 7, Windows Server 2008, Windows Server 2008 R2 for x64-based Systems (KB2539636)
- Cumulative Security Update for Internet Explorer 8 for Windows Server 2008 R2 x64 Edition (KB2559049)
- Security Update for Microsoft .NET Framework 4 on Windows XP, Windows Server 2003, Windows Vista, Windows 7, Windows Server 2008, Windows Server 2008 R2 for x64-based Systems (KB2487367)
- Security Update for Windows Server 2008 R2 x64 Edition (KB2567680)
- Security Update for Windows Server 2008 R2 x64 Edition (KB2563894)
- Security Update for Windows Server 2008 R2 x64 Edition (KB2536276)
- Update Rollup for ActiveX Killbits for Windows Server 2008 R2 x64 Edition (KB2562937)
- Windows Malicious Software Removal Tool x64 - August 2011 (KB890830)
- Security Update for Microsoft .NET Framework 3.5.1 on Windows 7 and Windows Server 2008 R2 SP1 for x64-based Systems (KB2539635)
- Security Update f

Finally at 3:24:44 AM:

Broadcom BCM5709C: The network link is down. Check to make sure the network cable is properly connected.

So it sort of seems like Windows Automatic Updates played a role in this going down. I don't believe it was simply the restart that caused the problem, as after fixing the IP address, etc., subsequent reboots have not cleared it out.