I’ve had a quite big C++ source file, copied from Windows with ^M symbol after each line. After any scrolling downside Emacs 24.2 hanged up and the only option was to kill it.
Due to the fact that my .emacs configuration is quite big, I started with binary search, commenting out parts of lisp code. After few minutes I’ve figured out, that the problem lies in .gnu-emacs file, so I moved with binary search to that file.
Within 5 minutes, source of the problem was found:
(setq-default inhibit-eol-conversion t)
After commenting this line, Emacs was resurrected!