Made some tests. Note that 

engine-setup --> fails
engine-cleanup --> ok
engine-setup --> fails again with same error about CA

while
engine-setup --> fails at
Creating CA...                                                  [ ERROR ]
Failed to create certificate authority
engine-setup again --> ok for the CA step but

Creating CA...                                                     [ DONE ]
Updating ovirt-engine service...                                   [ DONE ]
Setting Database Configuration...                                  [ DONE ]
Setting Database Security...                                       [ DONE ]
Creating Database...                                            [ ERROR ]
Failed updating configuration parameter: Error: failed updating configuration field LocalAdminPassword to ********

In logfile:
2012-12-20 16:39:26::DEBUG::common_utils::424::root:: Executing command --> '/usr/bin/engine-config -s 
LocalAdminPassword --admin-pass-file=/tmp/tmpahrM5u --cver=general -p /usr/share/ovirt-engine/conf/engi
ne-config-install.properties'
2012-12-20 16:39:28::DEBUG::common_utils::462::root:: output = 
2012-12-20 16:39:28::DEBUG::common_utils::463::root:: stderr = Error setting LocalAdminPassword's value. Failed to encrypt the current value

2012-12-20 16:39:28::DEBUG::common_utils::464::root:: retcode = 1
2012-12-20 16:39:28::DEBUG::setup_sequences::62::root:: Traceback (most recent call last):
  File "/usr/share/ovirt-engine/scripts/setup_sequences.py", line 60, in run
    function()
  File "/usr/bin/engine-setup", line 1112, in _updateVDCOptions
    raise Exception(output_messages.ERR_FAILED_UPD_VDC_OPTIONS%(sys.exc_info()[1]))
Exception: Failed updating configuration parameter: Error: failed updating configuration field LocalAdminPassword to ********

Gianluca