It doesn't matter as that is irrelevant as 7.2 is old now and if you look at http://www.sabayonlinux.org/sabayon/pkg ... 86-3.5.txt
you will see:x11-base/xorg-x11-7.3
so your version is newer and should be fine
You got to be able to think out side of the box when using linux. The wikis are great, but you have to use what is relevant and keep on moving. If you get stuck, always turn towards the official documentation to help.
You really should spend some time getting to know the package managers before using them. Our wiki explains using entropy and portage. Another thing you are gonna want to look at is the gentoo handbook located on gentoo.org. It goes through the entire operating system and very well documented. Gentoo itself is very well documented and all the user has to do is take some time and read through them. I say this as you are very new and it will benefit you greatly and save you a lot of time posting and waiting for a reply. This distro isn't the easiest for people new to it, not "newb" friendly, but highly learnable. ATI issues with linux go back a long ways, but has improved.
Using a gentoo based distro will teach more about linux and hardware than any other distro.