When booting a 2.4 kernel after an upgrade to FC2 or FC3-test, the
mouse doesn't function, because of the usage of /dev/input/mice for
2.6 kernels instead of /dev/psaux and IMPS/2 instead of the real mouse
protocol.

X
=================================================================

For X this can be fixed by making /dev/input/mice, IMPS/2 the
CorePointer, and the original mouse config AlwaysCore

The current upgrade-path replaces the CorePointer config by
/dev/input/mice, IMPS/2. Resulting in a config with both the
COrePointer and the AlwaysCore extra mouse pointing to
/dev/input/mice, since /dev/input/mice as AlwaysCore already was
present for USB support.

If you change the original mouse to AlwaysCore and the AlwaysCore
config there for USB to CorePointer, then X works fine under both 2.4
and 2.6.

gpm
=====================================================================

GPM is rather harder to fix, this because the upgrade changes
/etc/sysconfig/mouse. My suggestion don't touch /etc/sysconfig/mouse,
this should contain info about the real mouse, not the way the kernel
reports it.

Next modifiy /etc/rc.d/init.d/gpm to check what kernel is running:
-2.4 just use the info in /etc/sysconfig/mouse
-2.6 if its a PS/2 mouse use /dev/input/mice, IMPS/2, other wise
continue as usual.