iTerm emacs rendering issues on Intel Mac
If you have problems with emacs in iterm on an intel mac rendering which line you are on, making some lines and text invisible, or just in general not looking right, then the command line type:
TERM=xterm-color
then try running emacs. If that fixes the problem, add that line to your .bashrc or .tcshrc (or both) in your home directory so it always is run on iterm startup.