Help Needed - bootcamp problem - can't boot into leopard

hi there,
I have been using bootcamp with windows on my macbook for a number of months without issue. I've now got a problem as follows. When I try to boot my macbook it no longer boots at all, after a few minutes I get -


a black screen with a windows error relating to 'unable to read from disk' press ctrl+alt+del to reboot
if i hold down the option key when booting to try and boot into leopard the only options I get are for windows and the leopard install dvd (whick i just put in)
if I then select the leopard install dvd and use the disk utility to try and repair the disk it fails on both an attempt to verify the disk and attempting to repair the disk.

can anyone offer any advice on this, currently I can't use the laptop so any help appreciated
laptop is 3 years old, black macbook, running leopard and has been functioning fine up untill this problem appeared.

thanks