Movie Render Queue Motion Blur Issue

While rendering using MRQ I have encountered the same issue on two different projects. I have tried many different settings and I have narrowed it down to as it seems an issue with Motion Blur while using Anti Aliasing settings. In some samples, the more the samples the less it occurs, instead of the lens flare effect it renders out a black square on that position. As you understand I am trying to resolve the problem so I don’t need thousands of samples each time in order to hide the problem.