Disable USB on Install

hi,

i have a IBM i1300, 1171 6MU thinkpad.  it uses the ALi chipset
based USB implementation (usb-ohci i think).  whenever the usb-ohci
modules are modprobed, the machine just freezes.  apparently, this is a 
known issue.

i'm trying to put gentoo 1.2 on it.  i got the ISO off the site; but 
when i boot with it, it hangs on the line:

...
usb-ohci.c: usb-00:14.0, Acer Laboratories, Inc. [ALi] USB 1.1 
Controller

so anyway, i was wondering if i can disable USB in the kernel on the ISO 
or somehow build/download a kernel without anything USB related.

thank you very much,
xiaolei