I have what I think is a pretty decent SSAO system setup, but I get some odd artifacts near the edges where the random samples are off of the pre-rendered depth/normal buffer. In this screen shot I merely reject those samples, but you can see that at times they are all of the samples available given that there are a limited number of samples being taken. Anyway, you can see that the occlusion goes away toward the screen edges.
I was wondering if anyone had a better way of handling this? I also have tried clamping the samples and also if the screen x or y is negative, just negating it. All have had some rather unfortunate artifacts.