one reason I can think of is that other required services are not 'deployed' yet. E.g. if you have external jars with ejb's or cdi or… and those are not started yet, the jobexecutor cannot execute async services (which we do not have yet). But this is true for the engine in general.
I use the Activiti Spring integration and from the moment that the processEngineConfiguration bean is loaded (and the jobExector is active) the polling process begins.
I have an application server that hosts different web applications that communicatie through http. My Activiti workflow uses timeEvents. Suppose that the activiti appliction is started, a timer has reached the duedate and want to access functionallity in another application that is not yet started …
Maybe as a workaround, you could disable the jobExecutor activating by default, and using some kind of mechanism (like a BarrierService or listener of some kind) to call the jobexecutor.start() when container is booted.
