Moving devices from Zenoss 3.0.2 to Zenoss 4.2.5

I was making this:
$zenbatchdump > mydevicelist.txt
$zenbatchload mydevicelist.txt

Because I want to upgrade my system but in different servers
zenoss 3 ----> zenoss 4.2

But something happened in the middle of process ( only the half of devices was loaded in the new zenoss 4.2 ) , the screen was froze until a push Ctrl + D , and after that I couldn't see anything into the log's files, so, I decided to make the same, but when a run this:
$zenbatchload mydevicelist.txt

The script keep frozen and I could see in the log this:

the log:

2015-06-09T08:46:02 ERROR Products.Zuul.routers The id "Server" is invalid - it is already in use.
Traceback (most recent call last):
File "/opt/zenoss/Products/Zuul/routers/__init__.py", line 58, in addNode
organizer = facade.addOrganizer(contextUid, id, description)
File "/opt/zenoss/Products/Zuul/facades/__init__.py", line 191, in addOrganizer
context.manage_addOrganizer(id)
File "/opt/zenoss/Products/ZenModel/Organizer.py", line 191, in manage_addOrganizer
self._setObject(org.id, org)
File "/opt/zenoss/Products/ZenRelations/RelationshipManager.py", line 145, in _setObject
user, set_owner)
File "/opt/zenoss/Products/ZenRelations/PrimaryPathObjectManager.py", line 102, in _setObject
return ObjectManager._setObject(self, id, obj, roles, user, set_owner)
File "/opt/zenoss/lib/python/OFS/ObjectManager.py", line 325, in _setObject
v = self._checkId(id)
File "/opt/zenoss/Products/ZenRelations/RelCopySupport.py", line 48, in _checkId
checkValidId(self, new_id)
File "/opt/zenoss/lib/python/OFS/ObjectManager.py", line 116, in checkValidId
'The id "%s" is invalid - it is already in use.' % id)
BadRequest: The id "Server" is invalid - it is already in use.

That's make sense because there are servers already in there ( only the half of them)
How I can skip the servers that are already loaded in the new zenoss ( 4.2)
There are anyway to do this
Thanks you!