The following message appears in OV:
started. Operator : SYSTEM Node : <$OPC_MGMTSV> Action : "%ovinstalldir%\bin\vmspiDiscovery.exe" -d 531927d0-b220-71e0-16a7-0a01cc800000
failed. Result : 1 Output : Error: Specified file was not found.
This happens at random.
This is an HP related error. Applicable to Agents v8.60.501 and v11.01.
Fix from HP should be available as of October, 2011.