wow win2000 is NTFS, right? i didn't know PM could do that..
What happens - the multi-boot dies on "chainloader+1"? Are you using two drives, or just two partitions? If you can boot to Linux OK then you can try to fix your /etc/grub.conf file..
To use WinXP (Also NTFS) I had to map one drive onto the other with
map hd(1,0) hd(0,0)
map hd(0,0) hd(1,0)
rootnoverify hd(1,0)
chainloader +1
then chainloader worked. To do it on two partitions of the same drive i think would be
map hd(0,1) hd(0,0)
map hd(0,0) hd(0,1)
rootnoverify hd(0,1)
chainloader +1
lemme know if it works - those commands may be incorrect but that is how to boot an NTFS drive - chainloader can't read NTFS in mid-stream, you have to trick it into booting Win altogether