Only half screen after fresh install [Solved]

[denier]

Firts of all, sorry for my bad english.
So, I made a fresh install of Sabayon x86_64 MATE on my machine with AMD Phenom x4 955 BE and ATI HD 4850 VaporX (I was running on Debian Testing before, but I couldn't get the OpenGL running nor with default nor with proprietary drivers so after I read some forums about sabayon where I saw that it supports ATI graphics without problems I decided to install it).
Installation went without any errors, but when the X loaded it freezed and only half of the screen was visible.
Now I tried to restart but it stayed the same, half of the screen is black, only bottom half is shown and I can't move with mouse (cursor isnt shown) and keyboard isnt working as well (I tried alt+f2, alt+tab, ctrl alt backspace)... but I can switch to another tty via ctrl alt f2 (f*). I tried to update ati-drivers but it showed me some errors with dependencies and masking I couldnt understand because I am noob to sabayon portage. So I used google and found out I should try to copy xorg.conf from installation media to my system.. I did that and after restart there was still half of the screen but some kind of windows poped up asking me for something (probably related to xorg.conf) with buttons. I tried to press enter to confirm the highlighted option but it didnt work, as before with alt+f2 etc.
So now I am writing this from Midori browser in Sabayon recovery mode where the X surprisingly work without any problems.
Any idea what should I do?

[denier]

Looks like I fixed it but I have no idea how I did it.
I only installed xf86-video-ati, 12.6beta pre897 ati catalyst drivers and mesa utils in recovery mode and now X starts without any problem.