If they can't see the forum them that is the first option to check in trouble makers group Forum Permissions "Can see forum" in group management. I'll BET THE FORUMS ARE TURNED OFF
I will bet you did not really copy the same settings from users to troublemakers. The process can be a little misleading.
Currently editing permissions for: trouble makers
Copy Permissions from: USERS
Then you need to scroll down to the bottom of screen
Select Update group permissions.
Then go back and see what "Can see forums" is set to. AND SET THE OTHER PERMISSIONS SPECIAL TO THE TROUBLE MAKERS GROUP
