Premission denied when trying to init xend

Trying to start xend on Ubuntu 8.04:

# tail -n 30 /var/log/xen/xend.log
[2008-05-08 15:02:12 4791] DEBUG (XendDomain:601) cleanup_domains
[2008-05-08 15:02:12 4787] INFO (SrvDaemon:219) Xend exited with status 0.
[2008-05-08 15:09:08 4854] INFO (SrvDaemon:331) Xend Daemon started
[2008-05-08 15:09:08 4854] INFO (SrvDaemon:335) Xend changeset: unavailable.
[2008-05-08 15:09:08 4854] INFO (SrvDaemon:342) Xend version: Unknown.
[2008-05-08 15:09:08 4854] ERROR (SrvDaemon:353) Exception starting xend ((13, 'Permission denied'))
Traceback (most recent call last):
  File "/usr/lib64/python/xen/xend/server/SrvDaemon.py", line 345, in run
    servers = SrvServer.create()
  File "/usr/lib64/python/xen/xend/server/SrvServer.py", line 254, in create
    root.putChild('xend', SrvRoot())
  File "/usr/lib64/python/xen/xend/server/SrvRoot.py", line 40, in __init__
    self.get(name)
  File "/usr/lib64/python/xen/web/SrvDir.py", line 82, in get
    val = val.getobj()
  File "/usr/lib64/python/xen/web/SrvDir.py", line 52, in getobj
    self.obj = klassobj()
  File "/usr/lib64/python/xen/xend/server/SrvNode.py", line 30, in __init__
    self.xn = XendNode.instance()
  File "/usr/lib64/python/xen/xend/XendNode.py", line 658, in instance
    inst = XendNode()
  File "/usr/lib64/python/xen/xend/XendNode.py", line 83, in __init__
    self.other_config["xen_pagesize"] = self.xeninfo_dict()["xen_pagesize"]
  File "/usr/lib64/python/xen/xend/XendNode.py", line 622, in xeninfo_dict
    return dict(self.xeninfo())
  File "/usr/lib64/python/xen/xend/XendNode.py", line 572, in xeninfo
    info['xen_scheduler'] = self.xenschedinfo()
  File "/usr/lib64/python/xen/xend/XendNode.py", line 562, in xenschedinfo
    sched_id = self.xc.sched_id_get()
Error: (13, 'Permission denied')