C# と VB.NET の質問掲示板

いつも参考にさせてもらっています。またよろしくお願いします

WindowService内OnShutDown時に一定の処理を実行させてたいのですが(例えば5分)
およそ2分でシャットダウン処理が終わってしまいます
ログにも"シャットダウン完了"が記録されません
OnStopは正常に動作します

何か考えられる原因＆解決策はないでしょうか？

試したこと
・CanShutDownをTrueに設定
・レジストリ 
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\WaitToKillServiceTimeoutを360000に設定
・下記修正プログラム適用(実運用環境ではインストールできず)
http://support.microsoft.com/kb/2549760/ja

環境(どちらも動作しません)
・テスト環境
Windows7SP1 FrameWork2.0
・実運用環境
WindowsServer2008Sp1 FrameWork2.0


サンプルのテストプログラム
Public Class ServiceTest
    Const RunningTime As Integer = 5 * 60 * 1000 '最大で一時間くらい
    Const CheckTime As Integer = 4 * 1000
    Const WaitTime As Integer = 5 * 1000
    Private Running As Boolean

    Protected Overrides Sub OnStart(ByVal args() As String)
        PutLog("サービス開始")
    End Sub

    Protected Overrides Sub OnStop()
        PutLog("サービスストップ開始")
        ExecuteWait()
        While Running
            Me.RequestAdditionalTime(CheckTime)
            System.Threading.Thread.Sleep(WaitTime)
        End While
        PutLog("サービスストップ完了")
    End Sub

    Protected Overrides Sub OnShutdown()
        PutLog("シャットダウン開始")
        ExecuteWait()
        While Running
            System.Threading.Thread.Sleep(WaitTime)
        End While
        PutLog("シャットダウン完了")
        MyBase.OnShutdown()
    End Sub

    Private Delegate Sub AsyncMethodCaller(<Runtime.InteropServices.Out()> ByRef ThreadId As Integer)

    Private Sub CallbackMethod(ByVal ar As IAsyncResult)
        Dim Result As Runtime.Remoting.Messaging.AsyncResult = CType(ar, Runtime.Remoting.Messaging.AsyncResult)
        Dim Caller As AsyncMethodCaller = CType(Result.AsyncDelegate, AsyncMethodCaller)
        Dim ThreadId As Integer = 0
        Caller.EndInvoke(ThreadId, ar)
    End Sub

    Private Sub ExecuteWait()
        Running = True
        Dim Caller As New AsyncMethodCaller(AddressOf WaitAsync)
        Dim ThreadId As Integer = 0
        Dim Result As IAsyncResult = Caller.BeginInvoke(ThreadId, AddressOf CallbackMethod, Nothing)
    End Sub

    Private Sub WaitAsync()
        System.Threading.Thread.Sleep(RunningTime)
        Running = False
    End Sub

    Public Overloads Sub PutLog(ByVal ParamArray MessageList() As String)
        'ログ出力
        Try
            If MessageList IsNot Nothing Then
                Dim LogFileName As String = My.Application.Info.DirectoryPath + "\" + ServiceName + Today.ToString("yyyyMMdd") + ".log"
                Using File As New IO.FileStream(LogFileName, IO.FileMode.Append, IO.FileAccess.Write, IO.FileShare.Read)
                    Using LogStream As New System.IO.StreamWriter(File, System.Text.Encoding.GetEncoding("Shift-Jis"))
                        Dim LogValue As String = Now.ToString("yyyy/MM/dd HH:mm:ss.fff")
                        For Each Message As String In MessageList
                            LogValue += ",""" + Message.Replace("""", """""") + """"
                        Next
                        LogStream.WriteLine(LogValue)
                        LogStream.Flush()
                    End Using
                End Using
            End If
        Catch ex As Exception
        End Try
    End Sub
End Class