Good Job!
Nearly perfect ...  only some error message left when doing 'sudo update-grub':

josef@josef-maxtor-quad:~$ sudo dmsetup ls --tree
[sudo] password for josef: 
via_jehhchjje9 (252:8)
 └─via_jehhchjje (252:1)
    ├─ (8:128)
    └─ (8:112)
via_jehhchjje8 (252:7)
 └─via_jehhchjje (252:1)
    ├─ (8:128)
    └─ (8:112)
via_jehhchjje7 (252:6)
 └─via_jehhchjje (252:1)
    ├─ (8:128)
    └─ (8:112)
via_jehhchjje6 (252:5)
 └─via_jehhchjje (252:1)
    ├─ (8:128)
    └─ (8:112)
via_jehhchjje5 (252:4)
 └─via_jehhchjje (252:1)
    ├─ (8:128)
    └─ (8:112)
via_jehhchjje3 (252:3)
 └─via_jehhchjje (252:1)
    ├─ (8:128)
    └─ (8:112)
via_jehhchjje2 (252:2)
 └─via_jehhchjje (252:1)
    ├─ (8:128)
    └─ (8:112)
via_jehhchjje1 (252:0)
 └─via_jehhchjje (252:1)
    ├─ (8:128)
    └─ (8:112)
josef@josef-maxtor-quad:~$ sudo update-grub
Generating grub.cfg ...
Found linux image: /boot/vmlinuz-3.2.0-35-generic
Found initrd image: /boot/initrd.img-3.2.0-35-generic
ERROR: ddf1: seeking device "/dev/dm-3" to 18446744073709421056
ERROR: hpt37x: seeking device "/dev/dm-3" to 4608
ERROR: hpt45x: seeking device "/dev/dm-3" to 18446744073709547008
ERROR: isw: seeking device "/dev/dm-3" to 18446744073708469760
ERROR: sil: seeking device "/dev/dm-3" to 18446744073709289984
ERROR: ddf1: seeking device "/dev/dm-3" to 18446744073709421056
ERROR: hpt37x: seeking device "/dev/dm-3" to 4608
ERROR: hpt45x: seeking device "/dev/dm-3" to 18446744073709547008
ERROR: isw: seeking device "/dev/dm-3" to 18446744073708469760
ERROR: sil: seeking device "/dev/dm-3" to 18446744073709289984
ERROR: ddf1: seeking device "/dev/dm-3" to 18446744073709421056
ERROR: hpt37x: seeking device "/dev/dm-3" to 4608
ERROR: hpt45x: seeking device "/dev/dm-3" to 18446744073709547008
ERROR: isw: seeking device "/dev/dm-3" to 18446744073708469760
ERROR: sil: seeking device "/dev/dm-3" to 18446744073709289984
ERROR: ddf1: seeking device "/dev/dm-3" to 18446744073709421056
ERROR: hpt37x: seeking device "/dev/dm-3" to 4608
ERROR: hpt45x: seeking device "/dev/dm-3" to 18446744073709547008
ERROR: isw: seeking device "/dev/dm-3" to 18446744073708469760
ERROR: sil: seeking device "/dev/dm-3" to 18446744073709289984
ERROR: ddf1: seeking device "/dev/dm-3" to 18446744073709421056
ERROR: hpt37x: seeking device "/dev/dm-3" to 4608
ERROR: hpt45x: seeking device "/dev/dm-3" to 18446744073709547008
ERROR: isw: seeking device "/dev/dm-3" to 18446744073708469760
ERROR: sil: seeking device "/dev/dm-3" to 18446744073709289984
ERROR: ddf1: seeking device "/dev/dm-3" to 18446744073709421056
ERROR: hpt37x: seeking device "/dev/dm-3" to 4608
ERROR: hpt45x: seeking device "/dev/dm-3" to 18446744073709547008
ERROR: isw: seeking device "/dev/dm-3" to 18446744073708469760
ERROR: sil: seeking device "/dev/dm-3" to 18446744073709289984
ERROR: ddf1: seeking device "/dev/dm-3" to 18446744073709421056
ERROR: hpt37x: seeking device "/dev/dm-3" to 4608
ERROR: hpt45x: seeking device "/dev/dm-3" to 18446744073709547008
ERROR: isw: seeking device "/dev/dm-3" to 18446744073708469760
ERROR: sil: seeking device "/dev/dm-3" to 18446744073709289984
ERROR: ddf1: seeking device "/dev/dm-3" to 18446744073709421056
ERROR: hpt37x: seeking device "/dev/dm-3" to 4608
ERROR: hpt45x: seeking device "/dev/dm-3" to 18446744073709547008
ERROR: isw: seeking device "/dev/dm-3" to 18446744073708469760
ERROR: sil: seeking device "/dev/dm-3" to 18446744073709289984
ERROR: ddf1: seeking device "/dev/dm-3" to 18446744073709421056
ERROR: hpt37x: seeking device "/dev/dm-3" to 4608
ERROR: hpt45x: seeking device "/dev/dm-3" to 18446744073709547008
ERROR: isw: seeking device "/dev/dm-3" to 18446744073708469760
ERROR: sil: seeking device "/dev/dm-3" to 18446744073709289984
ERROR: ddf1: seeking device "/dev/dm-3" to 18446744073709421056
ERROR: hpt37x: seeking device "/dev/dm-3" to 4608
ERROR: hpt45x: seeking device "/dev/dm-3" to 18446744073709547008
ERROR: isw: seeking device "/dev/dm-3" to 18446744073708469760
ERROR: sil: seeking device "/dev/dm-3" to 18446744073709289984
ERROR: ddf1: seeking device "/dev/dm-3" to 18446744073709421056
ERROR: hpt37x: seeking device "/dev/dm-3" to 4608
ERROR: hpt45x: seeking device "/dev/dm-3" to 18446744073709547008
ERROR: isw: seeking device "/dev/dm-3" to 18446744073708469760
ERROR: sil: seeking device "/dev/dm-3" to 18446744073709289984
ERROR: ddf1: seeking device "/dev/dm-3" to 18446744073709421056
ERROR: hpt37x: seeking device "/dev/dm-3" to 4608
ERROR: hpt45x: seeking device "/dev/dm-3" to 18446744073709547008
ERROR: isw: seeking device "/dev/dm-3" to 18446744073708469760
ERROR: sil: seeking device "/dev/dm-3" to 18446744073709289984
ERROR: ddf1: seeking device "/dev/dm-3" to 18446744073709421056
ERROR: hpt37x: seeking device "/dev/dm-3" to 4608
ERROR: hpt45x: seeking device "/dev/dm-3" to 18446744073709547008
ERROR: isw: seeking device "/dev/dm-3" to 18446744073708469760
ERROR: sil: seeking device "/dev/dm-3" to 18446744073709289984
ERROR: ddf1: seeking device "/dev/dm-3" to 18446744073709421056
ERROR: hpt37x: seeking device "/dev/dm-3" to 4608
ERROR: hpt45x: seeking device "/dev/dm-3" to 18446744073709547008
ERROR: isw: seeking device "/dev/dm-3" to 18446744073708469760
ERROR: sil: seeking device "/dev/dm-3" to 18446744073709289984
ERROR: ddf1: seeking device "/dev/dm-3" to 18446744073709421056
ERROR: hpt37x: seeking device "/dev/dm-3" to 4608
ERROR: hpt45x: seeking device "/dev/dm-3" to 18446744073709547008
ERROR: isw: seeking device "/dev/dm-3" to 18446744073708469760
ERROR: sil: seeking device "/dev/dm-3" to 18446744073709289984
ERROR: ddf1: seeking device "/dev/dm-3" to 18446744073709421056
ERROR: hpt37x: seeking device "/dev/dm-3" to 4608
ERROR: hpt45x: seeking device "/dev/dm-3" to 18446744073709547008
ERROR: isw: seeking device "/dev/dm-3" to 18446744073708469760
ERROR: sil: seeking device "/dev/dm-3" to 18446744073709289984
Found openSUSE 11.3 (x86_64) on /dev/sda1
Found Ubuntu 9.04 (9.04) on /dev/sda3
Found Ubuntu 11.10 (11.10) on /dev/sdf5
Found Debian GNU/Linux (wheezy/sid) on /dev/sdf7
Found Windows 7 (loader) on /dev/sdg1
Found Windows 7 (loader) on /dev/mapper/via_jehhchjje1
Found Windows Vista (loader) on /dev/mapper/via_jehhchjje2
Found openSUSE 12.2 (x86_64) on /dev/mapper/via_jehhchjje7
Found Ubuntu 11.10 (11.10) on /dev/mapper/via_jehhchjje8
done

next step: i will try to upgrade now on /dev/mapper/via_jehhchjje8 from ubuntu 11.10 to ubuntu 12.04 
(i will add your repo before and after the upgrade)

shall i give it a try already?