vSphere collector issue

I've got ZenOSS collecting data from four vcenters. Two of these are standalone (lets call them SAVC1 and SAVC2) and zenoss is collecting all of the perf and event data as expected.

The other two (VCDVC1 and VCDVC2), which are sitting behind vCloud Director, are giving me event data and datastore usage data but all other perf data (so perf data for hosts, clusters, vms etc) is not being collected. VCDVC1/2 are not showing any errors in the vcenter logs, the firewalls are picking up anything but ZenOSS gives me the following when i model them;
"applyUpdateSets called with an incomplete suspended change (version=0_30) - storing until the remainder of the change is received"

There are also timeout errors like this in the zenvsphere log;
"2015-02-06 15:42:48,998 ERROR zen.vSpherePerfCollector: [task: VCDVC1-perf] User timeout caused connection failure.
Traceback (most recent call last):
File "/opt/zenoss/ZenPacks/ZenPacks.zenoss.vSphere-3.1.0-py2.7.egg/ZenPacks/zenoss/vSphere/perfcollector.py", line 303, in collect
VIM_PORT_TYPE, 'queryPerf', perf_manager, specs_chunk)
TimeoutError: User timeout caused connection failure.
2015-02-06 15:42:49,000 ERROR zen.vSphere: [task: VCDVC1-perf] Session error in perf collection from device VCDVC1 (txvsphere connection transport disconnected)
Traceback (most recent call last):
File "/opt/zenoss/ZenPacks/ZenPacks.zenoss.vSphere-3.1.0-py2.7.egg/ZenPacks/zenoss/vSphere/zenvsphere.py", line 676, in doTask
result = yield perfcollector.collect(config)
File "/opt/zenoss/lib/python/twisted/internet/defer.py", line 1018, in _inlineCallbacks
result = result.throwExceptionIntoGenerator(g)
File "/opt/zenoss/lib/python/twisted/python/failure.py", line 350, in throwExceptionIntoGenerator
return g.throw(self.type, self.value, self.tb)
File "/opt/zenoss/ZenPacks/ZenPacks.zenoss.vSphere-3.1.0-py2.7.egg/ZenPacks/zenoss/vSphere/perfcollector.py", line 307, in collect
raise e
TxvCoprocessIPCException: txvsphere connection transport disconnected"

Any ideas