Tested happening with:
Distribution: Gentoo Linux 
Hardware Environment: Mouse trust ami mouse 250s (3 buttons),or Micro
Innovations Model PD430P (first is optical, second should also)
Software Environment: all: after psmouse is loaded, just moving the mouse will
turn it off, and stays off even after reboot!!!!!! (unplug-replug to see the
optical-sensor/red-light on another time...)
Problem Description: /drivers/input/psmouse-base.c : 3 occurrency of 
PSMOUSE_CMD_RESET_DIS, two of which will happens on every ImEx mouse.

Steps to reproduce:
Buy a newer, cheap optical mouse, as (3 button, new model:)TRUST AMI MOUSE 250S
or Micro Innovations Model PD430P, plug with 2.6.13 kernels, and move it.
Led will turn off, and will stay off even after reboot, even rebooting to
different SO that would use it normally. Only chanche is to unplug/replug.

Ah, if informations aren't enough, there's a 4 pagae forum thread, ending
with an hack I'm using to make it work (is an hack just cause I don't know 
why PSMOUSE_CMD_RESET_DIS was used, I just commented out). Here:
http://forums.gentoo.org/viewtopic-p-2761606.html#2761606