USB mouse won't work

[Marcos B <marcosnospam@free.fr>]

Hello,

I have an Acer Travelmate 800 laptop,
I'm running Woody, on kenel 2.6.4 and I have have problems with my USB 
mouse.
Hotplug doesn't start it at boot time (even with /etc/init.d/hotplug 
restart).

It is an optical mouse, so I can see that the red light remains off.
This same mouse works very well on my second computer (Debian Sid, 
kernel 2.6.4).

I don't understand why it doesn't work on my laptop.

I tried "cat /dev/input/mice" and "cat /dev/psaux", but it answers only 
to my touchpad (synaptics, working pretty well).

I have looked at the loaded modules :
Module                  Size  Used by
ehci_hcd               25088  0
usbcore               101012  3 ehci_hcd
soundcore               9952  0
ide_cd                 39360  0
cdrom                  35872  1 ide_cd
ndiswrapper            60792  0
ntfs                   86932  0
8250                   17920  0
serial_core            22016  1 8250

hid is not loaded, so I did a modprobe hid,it returned no error but it 
still doesn't appear in my lsmod.
I put hid in /etc/modules, reboot : same result.

Is there another missing module ?
Do I need some driver ?

here is my dmesg after I boot (it seems to recognize only my touchpad):
[...]
Console: switching to colour frame buffer device 175x65
mice: PS/2 mouse device common for all mice
serio: i8042 AUX port at 0x60,0x64 irq 12
Synaptics Touchpad, model: 1
 Firmware: 5.8
 180 degree mounted touchpad
 Sensor: 29
 new absolute packet format
 Touchpad has extended capability bits
 -> 4 multi-buttons, i.e. besides standard buttons
 -> multifinger detection
 -> palm detection
input: SynPS/2 Synaptics TouchPad on isa0060/serio1
serio: i8042 KBD port at 0x60,0x64 irq 1
input: AT Translated Set 2 keyboard on isa0060/serio0
[...]

Can someone help me ?
Thanks

MArcos