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Description of problem:
Following compiling a custom kernel (from kernel-source-2.4.20-20.9) with the
ACPI patches from http://acpi.sourceforge.net/, the mouse and touchpad on my
notebook behave incorrectly. The system I am running is 

Compaq Presario 2100 Series Notebook (2133AC)
AMD Mobile Athlon 2400+
256MB DDR RAM
Synaptic Touchpad / USB Mouse / PS/2 Mouse

After patching the kernel source with the 2.4.20 version of the ACPI patch, the
kernel compiled and installed as expected. However, several things went awry.

First, booting the system with a USB mouse inserted did not enable the mouse
(i.e. no pointer motion, no click capability). A check of "lsmod" showed that
all appropriate modules had loaded (usbcore, usb-mouse, mousedev, usb-uhci,
hid). Further, when removing the mouse and enabling the Touchpad, the mouse
exhibited erratic behaviour (randomly darting around the screen and clicking
randomly, even though no buttons were clicked). The only resolution was to
switch to virtual terminal #1 and restart X.

Secondly, if the laptop was booted with the Touchpad enabled, inserting the PS/2
mouse caused the laptop to switch off the Touchpad as expected, but the PS/2
mouse was not enabled. Further, re-enabling the Touchpad caused the same erratic
mouse behaviour described above.

Finally, booting the system with a PS/2 mouse inserted works as expected.
However, removing the mouse to re-enable the Touchpad will enable the Touchpad
as expected, but will cause the same erratic behaviour described above.

Version-Release number of selected component (if applicable):


How reproducible:
Always

Steps to Reproduce:
1. Boot the laptop with a USB mouse inserted, then enable the touchpad;
OR
1. Boot the laptop with the touchpad enabled, then insert a PS/2 mouse, then
remove the PS/2 mouse;
OR
1. Boot the laptop with a PS/2 mouse inserted, then remove the PS/2 mouse.
    

Additional info: