MCMS Resource image handler

I’ve been working on rendering resources from MCMS using an HttpHandler. Now I’ve written a class to handle image scaling and quality, and I’ve used this concept in large scale applications; however, I cannot seem to render resources from the Resource Gallery of MCMS consistently.

public void ProcessRequest(HttpContext context)
{
  try
  {
    // get the resource
    Resource resource =
    (Resource)CmsHttpContext.Current.Searches.GetByGuid(ResourceGuid);

    if (resource != null)
    {
      HttpCachePolicy policy = context.Response.Cache;

      policy.SetLastModified(resource.LastModifiedDate);
      policy.VaryByParams["w;h;r"] = true;
      
      Stream stream = resource.OpenReadStream();
      
      // Resize the image
      ImageResizer.ResizeImage(
        stream,
        context.Response.OutputStream,
        Width,
        Height,
        true);
    }
    else
    {
      context.Trace.Warn(
        "No Image",
        "Cannot retrieve resource: "
          + ResourceGuid);
      RenderNoImage(context);
    }
  }
  catch (Exception ex)
  {
    context.Trace.Write(ex.ToString());
    Controller.Errors.LogError(ex);
    RenderNoImage(context);
  }
}

I can get this handler to render effectively for the first few requests. After a few requests, the handler consistently fails to retrieve the Resource and the Searches object may even be null.