foo.cs

void HandleDoWork (object sender, DoWorkEventArgs e)
{
	while(running)
	{
		using (var pool = new NSAutoreleasePool ()) {
			CreateBitmaps();

			if(m_bitmapList.Count == 100)
			{
				while(m_bitmapList.Count > 0) 
				{
					Console.WriteLine("dispose");
					var temp = m_bitmapList[0];
					m_bitmapList.RemoveAt(0);
					temp.Dispose();
					temp = null;
				}

				m_bitmapList.Clear();
				m_bitmapList = new List<Bitmap>();
			}
			Console.WriteLine("new");
		}
	}
}