make this:

title           Linux Mint, kernel 2.6.22-14-xen
root            (hd0,2)
kernel          /boot/vmlinuz-2.6.22-14-xen root=/dev/sda3 ro quiet splash
initrd          /boot/initrd.img-2.6.22-14-xen
boot


look roughly like this (modifying where necessary):

title           Xen 3.1 / XenLinux 2.6
root            (hd0,0)
kernel          /boot/xen-3.1.0.gz
module          /boot/vmlinuz-2.6-xen root=/dev/hda1 ro
module          /boot/initrd.img-2.6.18-xen