Comment 8 for bug 20705

Not really sure why the driver order makes a difference, unless you suffered
from #12915 which we just fixed (first few modules listed in /etc/modules didn't
actually get plugged properly).

Amusingly, the reason you got this odd behaviour from X is because your core
input device is the synaptics touchpad -- so as long as that's there, X will
start. The fact that /dev/input/mice is missing just means it decides not to
bother with it. This is why we load the module early, so it exists by the time
X starts and we can be absolutely sure that any plugged or unplugged mice just
work because X doesn't know about it.

Anyway, sounds like you're all fixed up, so I'll close this.