If System Management Services (SMS) is stopped on the System Controller (SC), the Sun Management Center platform agent will also stop when the agent's next automatic cache refresh occurs, typically once every hour. This behavior occurs only when you start and stop the platform agent repeatedly for very short periods of time.
For example, if you repeatedly stop the platform agent for one minute, and start the platform agent for two minutes, this behavior would occur.
Workaround: Delay the frequency of starting and stopping the platform agent. For example, stop the agent for three minutes and start the agent for five minutes. If the Platform agent does stop, restart SMS, and then restart the Sun Management Center platform agent.