This may have been solved as I found a simmilar thread, but I want to be sure.
Issue: The first time you start Spark in Windows or Linux the IM Gateway icons/connections and search do not work. Upon a exit of Spark and then launching the applicaion again, it will work fine. It seems to continue to work fine after a reboot, but not a power down over night.
Client: Spark 2.5.6 on both Windows (XP) and Linux (Ubuntu).
Server: Openfire 3.3.2 using OpenLDAP
It is very consistant under my configuration. So if you need more info just ask.