Examining the logfiles for another problem (freeze) we found the following entries every 20 minute in the /var/log/vmware/hostd.log):

}
--2009-07-06 08:13:06.329 'App' 65541 error-- Failed to send response to the client: Broken pipe
--2009-07-06 08:33:06.575 'Vmomi' 98311 info-- Activation N5Vmomi10ActivationE:0x1894cc48 : Invoke done waitForUpdates on --vmodl.query.PropertyCollector:ha-property-collector--
--2009-07-06 08:33:06.575 'Vmomi' 98311 info-- Throw vmodl.fault.RequestCanceled
--2009-07-06 08:33:06.575 'Vmomi' 98311 info-- Result:
(vmodl.fault.RequestCanceled) {
dynamicType = <unset>,
msg = ""
}
--2009-07-06 08:33:06.577 'App' 98311 error-- Failed to send response to the client: Broken pipe
--2009-07-06 08:53:06.839 'Vmomi' 344076 info-- Activation N5Vmomi10ActivationE:0x1847fc50 : Invoke done waitForUpdates on --vmodl.query.PropertyCollector:ha-property-collector--
--2009-07-06 08:53:06.839 'Vmomi' 344076 info-- Throw vmodl.fault.RequestCanceled
--2009-07-06 08:53:06.840 'Vmomi' 344076 info-- Result:
(vmodl.fault.RequestCanceled) {
dynamicType = <unset>,
msg = ""
}

and on the other machine very similar with:

}
--2009-07-06 07:44:28.902 'App' 376844 error-- Failed to send response to the client: Broken pipe
--2009-07-06 08:04:29.314 'Vmomi' 16384 info-- Activation N5Vmomi10ActivationE:0xa847a40 : Invoke done waitForUpdates on --vmodl.query.PropertyCollector:ha-property-collector--
--2009-07-06 08:04:29.315 'Vmomi' 16384 info-- Throw vmodl.fault.RequestCanceled
--2009-07-06 08:04:29.315 'Vmomi' 16384 info-- Result:
(vmodl.fault.RequestCanceled) {
dynamicType = <unset>,
msg = ""
}
--2009-07-06 08:04:29.319 'App' 16384 error-- Failed to send response to the client: Broken pipe
--2009-07-06 08:24:29.721 'Vmomi' 376844 info-- Activation N5Vmomi10ActivationE:0xa8fde80 : Invoke done waitForUpdates on --vmodl.query.PropertyCollector:ha-property-collector--
--2009-07-06 08:24:29.723 'Vmomi' 376844 info-- Throw vmodl.fault.RequestCanceled
--2009-07-06 08:24:29.723 'Vmomi' 376844 info-- Result:
(vmodl.fault.RequestCanceled) {
dynamicType = <unset>,
msg = ""
}
--2009-07-06 08:24:29.726 'App' 376844 error-- Failed to send response to the client: Broken pipe
--2009-07-06 08:44:30.112 'Vmomi' 147466 info-- Activation N5Vmomi10ActivationE:0x1823c858 : Invoke done waitForUpdates on --vmodl.query.PropertyCollector:ha-property-collector--
--2009-07-06 08:44:30.112 'Vmomi' 147466 info-- Throw vmodl.fault.RequestCanceled
--2009-07-06 08:44:30.112 'Vmomi' 147466 info-- Result:
(vmodl.fault.RequestCanceled) {
dynamicType = <unset>,
msg = ""
}

Could somebody tell us why does it occur and how we can avoid it?