We recently too ran into a problem that was reported some time ago in our Google Group that Windows Server 2008 rebooted spontaneously when accessing using Utgard. While the issue was somewhat vague back then it disappeared from our radar and finally was forgotten.
This time we ran into the issue interfacing with another system and were able to find out that this is a major issue in Windows 2008 Server R2. The issue is known by Microsoft and a hotfix is available which solves the issue. Seems that not only Windows Server 2008 is affected but some other versions of Windows too.
Happy patching 😉