This is on Gentoo with vanilla 2.4.25.

I can't seem to get any response when I do a cat /dev/input/mice or cat /dev/usbmouse.

i have the following modules installed
mousedev
hid
input
usb-ohci <- it's a SIS mb
usbcore

I've tried taking out hid and putting ing usbmouse instead and having both in, but neither did any good.

From dmesg
USB HID v1.10 Mouse [Microsoft Microsoft 5-Button Mouse with IntelliEye(TM)] on usb1:2.0

usb.c: unable to get major 180 for usb devices

devfs_register(mice): could not append to parent, err: -17

mice: PS/2 mouse device common for all mice

spurious 8259A interrupt: IRQ7

not sure if that stuff was useful or not but please help me out

Found the solution. Had to enable CONFIG_USB_HIDINPUT (HID Input Layer Support) in kernel