Event stop firing in a loop-Collection of common programming errors

I have 2 subs like below, and when I make a loop with 1000 iterations and capturePicture() in it. after 700 iterations the event is not raised anymore. Can anyone help me?

 Public Sub capturePicture()
        Try
            AddHandler capturePic.FrameEvent2, AddressOf CaptureDone
            capturePic.GrapImg()
            Threading.Thread.Sleep(270)
        Catch ex As Exception
            RemoveHandler capturePic.FrameEvent2, AddressOf CaptureDone
        End Try
  End Sub


 Private Sub CaptureDone(ByVal e As Bitmap)
        Try
            Me.PictureBox1.Image = e
            PictureBox1.Image.Save(MakeFileNameWithAutoIncrement(MakeFolderNameForCurrentDate(MyFolderName) + "\" + MyTimeStampDatumVrijeme() + "_" + Filename4Cam + "-CAM1(" + CamEvent + ").JPG"), System.Drawing.Imaging.ImageFormat.Jpeg)
            RemoveHandler capturePic.FrameEvent2, AddressOf CaptureDone
        Catch ex As Exception
            RemoveHandler capturePic.FrameEvent2, AddressOf CaptureDone
        End Try 
    End Sub