I typically test render first using preview and, then, using final with the full screen. Because of the nature of this scenes and the fact that I was trying to cover up some artifacts that I couldn't understand on the right side by trees, I rendered it in full screen final mode a lot. I was satisfied that i had covered up the artifacts sufficiently. I, then rendered in user mode at 2400 x 1800 only adding a slight texture anti aliasing and the object mask setting in enable multi pass. That is the setting I usually use. When I went to open it in Photoshop, I noticed that the artifacts were blatant. I rerendered in final mode and did two screen captures. they are significantly different. I am using beta 292230.

How can that be?