If a Seam component that triggers a timmer is used, an exception may be throw in the JBoss starting:
13:55:53,646 ERROR [TimerImpl] Error invoking ejbTimeout: java.lang.RuntimeException: java.lang.IllegalStateException: Attempted to invoke a Seam component outside an initialized application
And it does make sense, since the timer service tries to execute a method of a seam component before the seam application is started. To solve this i think that EJBs that are seam components should only be started after all the aplications in the server get started, or something like this.
I tested it using a timer that generates a log (@Logger) at every minute, and restarting the server (the delayed timmer would be triggered before the Seam App is up).