I've found the Xorg file in /user/bin/Xorg.
Now what's happening is relatively odd. If I perform startx with my user, it loads KDE with sluggish performance, as if it has Xgl 3D desktop enabled (and therefore not working well).
If I startx as root, it boots gnome and everything is ok.
If I let linux boot in X, it loads my user's KDE well and I can work.
I removed both Xgl and Compiz packages and afterwards startx will not start at all:
Fatal server error:
No GLX modules loaded
dlopen: /usr/lib/xorg/modules/xgl/libxgl.so: cannot open shared object file: No such file or directory
Where can startx be doing something different from regular boot so it tries to load Xgl or 3D-like environment?