For me, one source of this problem is qemu/kvm. http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=578672 suggests setting SDL_VIDEO_ALLOW_SCREENSAVER=1 .
For me, one source of this problem is qemu/kvm. http:// bugs.debian. org/cgi- bin/bugreport. cgi?bug= 578672 suggests setting SDL_VIDEO_ ALLOW_SCREENSAV ER=1 .