[CentOS] Booting C 6.0 from C 5.7

I installed C 6.0 in an empty partition. It functioned.

Despite using the usually successful methods of booting into another operating system from C 5.7, I can't get into C 6.0

Tried:-

title C6-0 (2.6.32-71.el6.x86_64)

rootnoverify (hd0,6) chainloader +1

and

root (hd0,6) kernel /boot/vmlinuz-2.6.32-71.el6.x86_64 ro root=UUID=67c62872-0c69-451c-8412-3c218c0d2cb0 rd_NO_LUKS rd_NO_LVM rd_NO_MD rd_NO_DM LANG=en_US.UTF-8 SYSFONT=latarcyrheb-sun16 KEYBOARDTYPE=pc KEYTABLE=uk initrd /boot/initramfs-2.6.32-71.el6.x86_64.img

My default works:-

title CentOS 5.7 #6 (2.6.18-274.7.1.el5) root (hd0,0) kernel /boot/vmlinuz-2.6.18-274.7.1.el5 ro root=LABEL=d6sys ramdisk_size=600000 initrd /boot/initrd-2.6.18-274.7.1.el5.img

and so does Ubuntu

title Ubuntu 11.04 (chain) (2.6.38-8) rootnoverify (hd0,4) chainloader +1

but Centos 6.0 fails.

Advice appreciated.