Hi, Wat version of kernel are u using? ( #uname -r).
for usb support, u should use kernel 2.4 and above( i use bf24 kernel).
if u already use bf24, then maybe u can run modconf from console, and try to select module for usb support.
maybe this link will help, although the kernel i use is different, but the usb module is the same:
How to make a USB mouse work in Debian 3.0
after that, dont forget to restart
Hope it helps