It sounds like your team hasn't gotten the proper master settings from Jamba. Did you use the Jamba Guide for setup or just run the ISBoxer Wizard? I don't know the extent to which ISBoxer's setup effects Jamba's setup, so someone else will have to respond to that. But I'd start with the initial Jamba setup of the team to make sure that the master is actually assigned as master and the slaves as slaves in all the clients. This includes making sure the Communications Channel is set up under Core: Communications.

If it's not the setup of Jamba, then it's probably something in ISBoxer. Perhaps a conflict, perhaps something in the keymaps.

http://isboxer.com/forum/viewtopic.php?f=4&t=3653
http://isboxer.com/forum/viewtopic.php?f=18&t=4233
http://isboxer.com/forum/viewtopic.php?f=4&t=2105
http://www.dual-boxing.com/threads/2...-one-character