Maybe it's just a problem in new kernel device setting.
When do you run
Code:
dmesg | grep ^input
can you see somewhere in the output your mouse description ?
If you do, you can get proper devices f.E. in Handlers section of
Code:
cat /proc/bus/input/devices
output or just change device setting in rc.gpm and xorg.conf to /dev/input/mouse, it works most of time.
If don't, try to load kernel module for your mouse type. Logitech alone don't say anyting but if it's PS/2 mouse try
and try the above again.
Sorry I don't use Slackware's stock 2.6.x kernel package so I don't know now exactly what hardware support is compiled in.