Gnome 2.22 & FreeBSD 7 mouse configuration

I'm a newbie to both FreeBSD and Gnome.

I installed FreeBSD 7 and installed and configured Gnome 2.22.  Everything is working fine except that my
mouse does not work.  I have a USB mouse with a wheel.

The mouse works fine in the FreeBSD console but no luck with Gnome.  I've research the question and the answer
is always to edit the Xorg, XFree86 or X11 configuration files which I cannot find anywhere on my FreeBSD install.

I'm about to give up...please if someone knows where I can configure my mouse I need your help.

Thank you!

Ian