X server can't find mouse

[richard <richm@isomedia.com>]

Have run xf86config several times. At startx it seems to be loading but
then server crashes with fatal message that server can't find the mouse
-- no such file or device. It's just a regular 2-button mouse. Microsoft
protocol works fine with this mouse on the same box on another partition
with Red Hat and later Mandrake. 
I did try ln -s /dev/ttys0 /dev/mouse but it still didn't see it. I
don't know how to find or configure gpm or even what it is.
Everything else seems to behave fine.
What's missing? 

Thanks much

Richard