I always like to set LCD density to look like a higher resolution. So I tried 3 different apps to change it on the NC with MIUI 1.9.2 from the default 240 to 185. Each could change it with a reboot, but never would on subsequent startups, even if I checked apply density on boot. After some googling, I used Root Explorer to go into system/build.prop, and look for the lcd density setting-and it was 185, but not applying. So I looked around some more, and in data/local.prop, I found another place to change density. When I changed this one, it now boots with the value I changed it to. Thought I'd pass it along.