Quote - As regards rendered images, you do get more detail per square inch with Higher DPI settings in your "Render Dimensions" window, providing the Max.Texture setting in "Render Settings is suitably high.

Sure, more details when printed, but the rendered (=on screen) image would be the same, whichever DPI you use. From what I know DPI isn't used for textures, and if you look closer to the render dimensions dialog you can even see that it is greyed out if you use "match preview window": as this is only a way to say "render at that dimension in pixels" and the render is always visible in the preview window whichever dimension you use, can't see why it's greyed, if it's true what you say... Just on the topic at hand, though, I've noticed a worse image quality in the P7 renderer against P6, both in lightning and in texturing; for the latter I can blame texture filtering...but for the lights??? So, I think the problem lyes elsewhere than simple DPI settings...