Can you copy and paste (here) the information that is being spammed? (So I can identify where it is coming from.) With that I might be able to help you?

FYI:

The channel under /jamba -> Advanced -> Core: Communications has one and only one purpose. That purpose is to track which toons of your team are online. Each toon joins the channel you have configured upon logging in. Jamba polls that channel every 5 seconds looking at the list of characters subscribed to that channel. If a toon is in that list, then Jamba assumes the toon is online, likewise if the toon is not in the list, Jamba assumes the toon is offline.

However all this is unnecessary if you check the box that says "Assume All Team Members Always Online", as the channel checking is skipped. With this option, if a character isn't online, you get spammed "No player named '<toon name>' is currently playing. Regardless of whether this option is on or off, Jamba still tries to connect to the channel.