More ideas for those who are still having trouble with Jamba communications.

1) Try changing the options in the new Networking options section of World of Warcraft and see if that makes a difference.

2) Try checking "assume team is always online" under the advanced settings -or- uncheck this and change the private channel username and password and relog all your toons.

3) Disable all addons except Jamba (and ISBoxer if you use it) and see if Jamba behaves.

4) Disable the standalone Ace3 addon if you have it installed.