Thanks for the info!
It's true - we depend on the Heartbeat Status we receive from the VMware API. And, as you saw in that forum post - this information can be unreliable sometimes.
Best idea for the moment is probably to disable that Monitor, as advised; you still receive all other events and metrics related to VMs, so you still have good visibility of VM status.
Let's hope a VMware update will fix the stability of the Heartbeat alarms from VC.
Vice President, Product Management