This regression was introduced since http://bamboo.igniterealtime.org/browse/SPARK-INSTALL4J-589 (invisibility option patch)
Spark is trying to reconnect and doesn't say that it has failed, but shows offline status icon, doesn't load roster and for other clients remain offline. One have to select Online status to actually connect to the server. 588 build works fine. I haven't selected to login as Invisible option.