Mine

root@dual-xeon-3:/var/log# xm list
Traceback (most recent call last):
  File "/usr/sbin/xm", line 8, in ?
    from xen.xm import main
  File "/usr/lib/python/xen/xm/main.py", line 51, in ?
    from xen.util import security
  File "/usr/lib/python/xen/util/security.py", line 25, in ?
    from xen.lowlevel import acm
ImportError: /usr/lib/python/xen/lowlevel/acm.so: cannot open shared object file: No such file or directory
root@dual-xeon-3:/var/log#