12.10 - Unable to resize LVM partition just after Ubuntu install with 'use lvm' option

During installation of Ubuntu 12.10 x64 I checked the "Use LVM" option. My partitions:

• /dev/sda1, ext2, mount: /boot, 243.00 MiB, flag: boot


• /dev/sda2, extended, 698.4 GiB
  
  
  
  
  • /dev/sda5, lvm2 pv, mount: ubuntu, 698.4 GiB, flag: lvm
  
  

Or better see a GParted screenshot (am not allowed to post images)

I've tried both with current system and a live USB Ubuntu, but I can't do anything with the LVM partition: nor add a new subpartition, neither resize it. Is there a way to shrink it so I can add more physical partitions? Or how do I add a new virtual subpartition to LVM? (No such menu option in GParted)

EDIT sudo pvs:

PV         VG     Fmt  Attr PSize   PFree
/dev/sda5  ubuntu lvm2 a--  698.39g    0 

sudo vgs:

VG     #PV #LV #SN Attr   VSize   VFree
ubuntu   1   2   0 wz--n- 698.39g    0 

sudo lvs:

LV     VG     Attr     LSize   Pool Origin Data%  Move Log Copy%  Convert
root   ubuntu -wi-ao-- 692.49g                                           

swap_1 ubuntu -wi-ao--   5.91g