Version:
Folsom on RHEL6.4, openstack-packstack-2012.2.2-0.8.dev346.el6ost

Scenario:
I've configured packstack to use my ntp server (using the CONFIG_NTP_SERVERS entry), and installation failed because ntpdate can not run while ntpd is running on the same machine.

# /usr/sbin/ntpdate qa1.qa.lab.tlv.redhat.com
30 Jan 09:31:46 ntpdate[6598]: the NTP socket is in use, exiting



From packstack's output:

# packstack --answer-file=ANSWER_FILE
Welcome to Installer setup utility

Installing:
Clean Up...                                              [ DONE ]
Setting Up ssh keys...root.160.29's password: 
root.160.25's password: 
root.160.27's password: 
                                   [ DONE ]
OS support check...                                      [ DONE ]
Running Pre install scripts...                           [ DONE ]
Installing time synchronization via NTP...               [ DONE ]
Create MySQL Manifest...                                 [ DONE ]
Creating QPID Manifest...                                [ DONE ]
Creating Keystone Manifest...                            [ DONE ]
Adding Glance Keystone Manifest entries...               [ DONE ]
Creating Galnce Manifest...                              [ DONE ]
Adding Cinder Keystone Manifest entries...               [ DONE ]
Checking if the Cinder server has a cinder-volumes vg... [ DONE ]
Creating Cinder Manifest...                              [ DONE ]
Adding Nova API Manifest entries...                      [ DONE ]
Adding Nova Keystone Manifest entries...                 [ DONE ]
Adding Nova Cert Manifest entries...                     [ DONE ]
Adding Nova Compute Manifest entries...                  [ DONE ]
Adding Nova Network Manifest entries...                  [ DONE ]
Adding Nova Scheduler Manifest entries...                [ DONE ]
Adding Nova VNC Proxy Manifest entries...                [ DONE ]
Adding Nova Common Manifest entries...                   [ DONE ]
Creating OS Client Manifest...                           [ DONE ]
Creating OS Horizon Manifest...                          [ DONE ]
Adding Swift Keystone Manifest entries...                [ DONE ]
Creating OS Swift builder Manifests...                   [ DONE ]
Creating OS Swift proxy Manifests...                     [ DONE ]
Creating OS Swift storage Manifests...                   [ DONE ]
Creating OS Swift Common Manifests...                    [ DONE ]
Preparing Servers...                                     [ DONE ]
Running Post install scripts...                          [ DONE ]
Installing Puppet...                                     [ DONE ]
Copying Puppet modules/manifests...                      [ DONE ]
Applying Puppet manifests...
Applying /var/tmp/packstack/20130130-0927/manifests/10.35.160.29_prescript.pp
Applying /var/tmp/packstack/20130130-0927/manifests/10.35.160.25_prescript.pp
Applying /var/tmp/packstack/20130130-0927/manifests/10.35.160.27_prescript.pp
Testing if puppet apply is finished : 10.35.160.29_prescript.pp
Testing if puppet apply is finished : 10.35.160.25_prescript.pp OK
Testing if puppet apply is finished : 10.35.160.29_prescript.pp OK
Testing if puppet apply is finished : 10.35.160.27_prescript.pp OK
Applying /var/tmp/packstack/20130130-0927/manifests/10.35.160.29_ntpd.pp
Applying /var/tmp/packstack/20130130-0927/manifests/10.35.160.25_ntpd.pp
Applying /var/tmp/packstack/20130130-0927/manifests/10.35.160.27_ntpd.pp
Testing if puppet apply is finished : 10.35.160.29_ntpd.pp
Testing if puppet apply is finished : 10.35.160.25_ntpd.pp
ERROR:root:Error  during remote puppet apply of /var/tmp/packstack/20130130-0927/manifests/10.35.160.27_ntpd.pp
ERROR:root:notice: /File[ntp_config]/content: content changed '{md5}32a4dd13b44b8c5ec7ca69872ac7f796' to '{md5}fb26e2660091a638b10a00e2f15ccc2c'
err: /Stage[main]//Exec[ntpdate]/returns: change from notrun to 0 failed: /usr/sbin/ntpdate qa1.qa.lab.tlv.redhat.com returned 1 instead of one of [0] at /var/tmp/packstack/20130130-0927/manifests/10.35.160.27_ntpd.pp:73
notice: /Stage[main]//Service[ntpd]: Dependency Exec[ntpdate] has failures: true
warning: /Stage[main]//Service[ntpd]: Skipping because of failed dependencies
notice: Finished catalog run in 2.03 seconds

Testing if puppet apply is finished : 10.35.160.27_ntpd.pp                          [ ERROR ]
ERROR:root:Traceback (most recent call last):
  File "/usr/lib/python2.6/site-packages/packstack/installer/run_setup.py", line 806, in main
    _main(confFile)
  File "/usr/lib/python2.6/site-packages/packstack/installer/run_setup.py", line 593, in _main
    runSequences()
  File "/usr/lib/python2.6/site-packages/packstack/installer/run_setup.py", line 569, in runSequences
    controller.runAllSequences()
  File "/usr/lib/python2.6/site-packages/packstack/installer/setup_controller.py", line 57, in runAllSequences
    sequence.run()
  File "/usr/lib/python2.6/site-packages/packstack/installer/setup_sequences.py", line 154, in run
    step.run()
  File "/usr/lib/python2.6/site-packages/packstack/installer/setup_sequences.py", line 60, in run
    function()
  File "/usr/lib/python2.6/site-packages/packstack/plugins/puppet_950.py", line 123, in applyPuppetManifest
    waitforpuppet(currently_running)
  File "/usr/lib/python2.6/site-packages/packstack/plugins/puppet_950.py", line 111, in waitforpuppet
    validate_puppet_logfile(log)
  File "/usr/lib/python2.6/site-packages/packstack/modules/ospluginutils.py", line 137, in validate_puppet_logfile
    raise PackStackError(message)
PackStackError: Error during puppet run : err: /Stage[main]//Exec[ntpdate]/returns: change from notrun to 0 failed: /usr/sbin/ntpdate qa1.qa.lab.tlv.redhat.com returned 1 instead of one of [0] at /var/tmp/packstack/20130130-0927/manifests/10.35.160.27_ntpd.pp:73

Error during puppet run : err: /Stage[main]//Exec[ntpdate]/returns: change from notrun to 0 failed: /usr/sbin/ntpdate qa1.qa.lab.tlv.redhat.com returned 1 instead of one of [0] at /var/tmp/packstack/20130130-0927/manifests/10.35.160.27_ntpd.pp:73
Please check log file /var/tmp/packstack/20130130-0927/openstack-setup.log for more information