I am only familiar with Ubuntu and Windows, how does OSX handle the issue? Is it just bigger controls on the site or are you saying the actual resolution of the "hit-box" for these buttons isn't specific enough?
If I understand everything correctly, this issue is handled by Apple's "retina" technology. They basically combine every 4 pixel square into one sharp composite pixel. That way you get a crisp view that's readable while getting only a quarter of the workspace. You can scale your picture up to full resolution if you don't mind the small text/icons.