Hm, that's somewhat vague - exactly what stopped working?  Does the
machine crash? Or are you just unable to use certain usb devices? Please
provide the boot.msg file and hwinfo output.

Without a minimum of information we will not be able to do anything
useful with this report.

Sorry about the vagueness. When installing RC1, everything seems to proceed
properly through the point where YOU can be run. One of the updates listed is a
kernel update. After installing this update, the installer asks to reboot, and
upon reboot, USB devices no longer function as well as network devices. As I
only have access to a USB keyboard/mouse, I am unable to continue the installation. 

I am unable to get the boot.msg and hwinfo for you, as the keyboard and mouse do
not work. 

I don't know much about that update kernel for RC1; but I suggest trying 
with RC2 (or whatever the latest available release candidate is) 
 
(BTW there's an easy way to capture info even without keyboard etc - 
boot a working kernel; add these lines to /etc/init.d/boot.local: 
 
/sbin/dmesg > /tmp/boot.log 
/usr/sbin/hwinfo > /tmp/hwinfo 
 
then boot the broken kernel. 

RC1 is the latest publicly available RC. I've reinstalled without the kernel
update, and everything seems fine. I'll try the tip above later today with the
new kernel.

I will assume this one is fixed. Feel free to re-open if you encounter the
problem again.