Zenoss 4.2.5 unable to import PySamba.twisted.reactor on Ubuntu

Heya folks! We're running into a weird problem where Zenoss is not able to find/install the PySamba.twisted.reactor module despite the fact that it is installed and in sys.path (via easy-install.pth)

For instance:
zenoss:/usr/local/zenoss/ZenPacks$ python
Python 2.7.2 (default, Apr 25 2014, 10:00:33)
[GCC 4.6.3] on linux3
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> sys.path
['', '/usr/local/zenoss/lib/python2.7/site-packages/Zenoss-4.2.5-py2.7.egg', '/usr/local/zenoss/lib/python2.7/site-packages/readline-6.2.4.1-py2.7-linux-x86_64.egg', '/usr/local/zenoss/ZenPacks/ZenPacks.zenoss.PySamba-1.0.0-py2.7-linux-x86_64.egg/ZenPacks/zenoss/PySamba/lib', '/usr/local/zenoss/ZenPacks/ZenPacks.zenoss.PySamba-1.0.0-py2.7-linux-x86_64.egg', '/usr/local/zenoss/ZenPacks/ZenPacks.zenoss.WindowsMonitor-1.1.0-py2.7.egg', '/usr/local/zenoss/ZenPacks/ZenPacks.zenoss.ApacheMonitor-2.1.4-py2.7.egg', '/usr/local/zenoss/ZenPacks/ZenPacks.zenoss.DellMonitor-2.2.0-py2.7.egg', '/usr/local/zenoss/ZenPacks/ZenPacks.zenoss.DigMonitor-1.1.0-py2.7.egg', '/usr/local/zenoss/ZenPacks/ZenPacks.zenoss.DnsMonitor-2.1.0-py2.7.egg', '/usr/local/zenoss/ZenPacks/ZenPacks.zenoss.FtpMonitor-1.1.0-py2.7.egg', '/usr/local/zenoss/ZenPacks/ZenPacks.zenoss.HPMonitor-2.1.0-py2.7.egg', '/usr/local/zenoss/ZenPacks/ZenPacks.zenoss.HttpMonitor-2.1.0-py2.7.egg', '/usr/local/zenoss/ZenPacks/ZenPacks.zenoss.IRCDMonitor-1.1.0-py2.7.egg', '/usr/local/zenoss/ZenPacks/ZenPacks.zenoss.JabberMonitor-1.1.0-py2.7.egg', '/usr/local/zenoss/ZenPacks/ZenPacks.zenoss.LDAPMonitor-1.4.0-py2.7.egg', '/usr/local/zenoss/ZenPacks/ZenPacks.zenoss.NNTPMonitor-1.1.0-py2.7.egg', '/usr/local/zenoss/ZenPacks/ZenPacks.zenoss.NtpMonitor-2.2.0-py2.7.egg', '/usr/local/zenoss/ZenPacks/ZenPacks.zenoss.ZenJMX-3.9.6-py2.7.egg', '/usr/local/zenoss/ZenPacks/ZenPacks.zenoss.PySamba-1.0.0-py2.7.egg', '/usr/local/zenoss/ZenPacks/ZenPacks.zenoss.LinuxMonitor-1.2.1-py2.7.egg', '/usr/local/zenoss/ZenPacks/ZenPacks.zenoss.ZenossVirtualHostMonitor-2.4.0-py2.7.egg', '/usr/local/zenoss/ZenPacks/ZenPacks.zenoss.EsxTop-1.1.0-py2.7.egg', '/usr/local/zenoss/ZenPacks/ZenPacks.zenoss.XenMonitor-1.1.0-py2.7.egg', '/usr/local/zenoss/ZenPacks/ZenPacks.zenoss.DeviceSearch-1.2.0-py2.7.egg', '/usr/local/zenoss/ZenPacks/ZenPacks.zenoss.WBEM-1.0.0-py2.7.egg', '/usr/local/zenoss/ZenPacks/ZenPacks.zenoss.MySqlMonitor-3.0.0-py2.7.egg', '/usr/local/zenoss/ZenPacks/ZenPacks.community.Stingray-1.0.4.egg', '/usr/local/zenoss/ZenPacks/ZenPacks.community.OpenVMS-1.1.0-py2.7.egg', '/usr/local/zenoss/ZenPacks/ZenPacks.zenoss.Memcached-1.0.0.egg', '/usr/local/zenoss/ZenPacks/ZenPacks.community.NginxStatus-1.1.egg', '/usr/local/zenoss/ZenPacks/ZenPacks.community.OpenBSD-1.0.1-py2.7.egg', '/usr/local/zenoss/ZenPacks/ZenPacks.zenoss.OpenStack-1.2.2.egg', '/usr/local/zenoss/ZenPacks/ZenPacks.zenoss.PythonCollector-1.5.2.egg', '/usr/local/zenoss/ZenPacks/ZenPacks.zenoss.Microsoft.Windows-2.1.2.egg', '/usr/local/zenoss/lib/python', '/usr/local/zenoss/lib/python27.zip', '/usr/local/zenoss/lib/python2.7', '/usr/local/zenoss/lib/python2.7/plat-linux3', '/usr/local/zenoss/lib/python2.7/lib-tk', '/usr/local/zenoss/lib/python2.7/lib-old', '/usr/local/zenoss/lib/python2.7/lib-dynload', '/usr/local/zenoss/lib/python2.7/site-packages', '/usr/local/zenoss/ZenPacks']
>>> import PySamba.twisted.reactor
Traceback (most recent call last):
File "", line 1, in
ImportError: No module named PySamba.twisted.reactor
---------------------------------------------

When I go explicity into that module's python directory, I AM able to import it, however:
zenoss:/usr/local/zenoss/ZenPacks/ZenPacks.zenoss.PySamba-1.0.0-py2.7-linux-x86_64.egg/ZenPacks/zenoss$ python
Python 2.7.2 (default, Apr 25 2014, 10:00:33)
[GCC 4.6.3] on linux3
Type "help", "copyright", "credits" or "license" for more information.
>>> import PySamba.twisted.reactor
>>>

----------------------------------

As you can see from the sys.path above, I have tried explictly stating the entire full path to PySamba's lib directory, as suggested by http://community.zenoss.org/message/70358 but that has not had any affect.

Am I missing something obvious and/or doing something silly

Any help would be greatly appreciated!