I think I know what is the problem. I've made a small experiment. I put modified kexts with ATIinject and like it was before screen only blinks once, and system loads further. I see nothing but boot stripes but I've made screenshot, and then reboot, delete all ATI kext, login and I've got Picture on my desktop which is in res 1280x1024 and in my laptop should be 1280x800, so I think is the reason why screen only blinks. How can I change resolution? "Graphical Mode"="1280x800x32" at boot not works