Can't escape to loader prompt

[Matthew Huggett]

Hi,

I'm trying to install 5.3, via CD, on a system with a USB keyboard
only.  Once I boot from the CD, I lose the keyboard and, after the
first menu times out, I see the main install menu but I can't make any
selections.

I've seen the instructions to "escape to loader prompt" and do
> set hint.atkbd.0.flags="0x1"
> boot
However, I am unable to even escape to the loader prompt.  The only
thing I can do with my keyboard once I boot from the CD is toggle the
num lock and caps lock.  I haven't been able to find any reports of
similar trouble on Google, so was wondering if anyone on this list has
had trouble with a keyboard so early on in the install, and what, if
anything, they did to fix it.

Thanks,

Matt