Add these lines to /etc/rc.conf
If : Just a default xorg-7.4_2
If : You're using Gnome2
If : You're running KDE4
Alwayes send your xorg.conf entirely(with the exceptions of comments)
There's two type of free implementation of X11 -- current release
XFree86™ 4.4RC2 && Xorg 7.4
As of FreeBSD 5.3-RELEASE, the default flavor of X11 was changed to Xorg (Hot/Relax Licence!)
Starting with version 7.4, Xorg use HAL to autodetect keyboards and mice (Above Solution)
FreeBSD IS NOT Linux. Maxiumum differences are in kernel && base system, and a average but important differnce in third-party app/util compiling/installing.
So, If you want to use freeBSD you must review it's manuals from scratch.