My Debian Woody installation won't boot

[Dave Turner <dave_t_turner@mac.com>]

I have spent an unhappy Sunday afternoon trying to install the woody 
release onto my Rev A 233MHz iMac from CD-ROM.

As far as I can tell the actual install proceeds normally, then at 
the end when I agree to make the system bootable I am asked to remove 
the CD-ROM (which I do), and am rewarded by a blank grey screen and a 
locked machine.

I tried install24 and got same thing.
install24-safe is the closest I have got to something that might actually boot.

Open Firmware "printenv" shows the boot device as hd:2;,\\tbxi
(or something like that anyway)

if I type boot hd:2, yahboot (note the space between the comma and 
yahboot) then I get the response:-

MAC-PARTS: LOAD (noninterposed) not supportedload-size=0 adler32 =1
LOAD-SIZE is too small

if I type boot hd:2,yahboot
then the system just locks up.

Does anybody know what the problem is?
Does anyone know how I might fix it?
Has anyone got Woody up and running on a Rev A iMac?

DT - a definite Linux newbie