We have two build machines. Lately, we've migrated our projects to vs2010 from vs2005. But the problem is that one of the machines occurs error during build. Another machine works well, but just one machine shows error. The differences between the machines are os and computer spec. The machine which is working well is installed windows server 2003 and the other is windows7.

the error message is

unhandled exception: System.NullReferenceException: 
Microsoft.VisualStudio.Shell.ThreadHelper.InvokeOnUIThread(InvokableBase invokable)
Microsoft.VisualStudio.Shell.ThreadHelper.Invoke(Action action)Microsoft.VisualStudio.Project.VS.Implementation.VSShellServices.InvokeOnUIThread(Action method)
Microsoft.VisualStudio.Project.VisualC.VCProjectEngine.ApartmentMarshaler.Invoke(Action method)
Microsoft.VisualStudio.Project.VisualC.VCProjectEngine.VCConfigBuildJob.BuildCompleted(BuildSubmission ar)
Microsoft.VisualStudio.Project.Contracts.Implementation.BuildProjectBase.BuildCompletedCallbackManager.BuildCompleted(BuildSubmission buildSubmission)
Microsoft.Build.Execution.BuildSubmission.<CheckForCompletion>b__0(Object state)
System.Threading.QueueUserWorkItemCallback.WaitCallback_Context(Object state)
System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx)
System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
System.Threading.ThreadPoolWorkQueue.Dispatch()
System.Threading._ThreadPoolWaitCallback.PerformWaitCallback()

Curiously enough, when I run building project in command line on the machine which occurs error, it works well. The machine just shows error when launched by ccnet. I've installed latest version of ccnet to all machines. Is there anybody who faced like this problem?