Custom action servers run in a launch file problem

edit

Hi all, I've made two simple action server A and B and one action client C that can communicate with both. I experienced a really strange behaviour: if i put the two server nodes within a launch file along with the client and i use the "roslaunch" to run the launch file, the two servers seem to run, but the client waits for the server. If i use "rosrun" to run the 3 single nodes in three different terminals, everything works well. The sequence of running the nodes doesnt matter as long as if i run as first the client using rosrun it waits the server and when i run later one of the server with rosrun it works perfectly. Anyone have a solution? i absolutely need to run everything within a launch file.As i have highlighted, the problem is not connected with the node' code lines as long as running them through "rosrun" i have the results i need that's why i dont post the code. Anyway the launch file is this one

<?xml version="1.0"?>
<launch>
  <node pkg="action_test" type="GoDriveActionServer" name="GoDriveActionServer" launch-prefix="xterm -e" />
  <node pkg="action_test" type="TakeVideoActionServer" name="TakeVideoActionServer" launch-prefix="xterm -e" /> 
  <node pkg="action_test" type="ActionClient" name="ActionClient" launch-prefix="xterm -e" /> 
</launch>

Thanks in advance

UPDATE
I also tried to make the client as easy as possible without waiting for the servers, without feedbacks and done callbacks, but running the three nodes within a launch file doesn't allow the client to communicate with the servers, instead i don't have any problem if i run the three nodes separately, everyone in a single terminal.
This is so so strange.

UPDATE WITH CODE
I tried to remove the launch-prefix adding the output="screen" but nothing.
Launching "roswtf" after i run roslaunch action_test action_test.launch i get:

Loaded plugin tf.tfwtf
No package or stack in context
================================================================================
Static checks summary:

No errors or warnings
================================================================================
Beginning tests of your ROS graph. These may take awhile...
analyzing graph...
... done analyzing graph
running graph rules...
... done running graph rules

Online checks summary:

Found 1 warning(s).
Warnings are things that may be just fine, but are sometimes at fault

WARNING The following node subscriptions are unconnected:
 * /SimpleActionClient:
   * /go_drive/feedback
   * /take_video/status
   * /go_drive/result
   * /take_video/result
   * /go_drive/status
   * /take_video/feedback
 * /GoDriveActionServer:
   * /GoDriveActionServer/cancel
   * /GoDriveActionServer/goal
 * /TakeVideoActionServer:
   * /TakeVideoActionServer/cancel
   * /TakeVideoActionServer/goal

so i think there's nothing wrong
The code for the go_drive server is something like this (it's the same for the take video):

#include <ros/ros.h>
#include <actionlib/server/simple_action_server.h>
#include <action_test/GoDriveAction.h>

class GoDriveAction
{
protected:

  ros::NodeHandle nh_;
  actionlib::SimpleActionServer<action_test::GoDriveAction> as_;
  std::string action_name_;
  // create messages that are used to published feedback/result
  action_test::GoDriveFeedback feedback_;
  action_test::GoDriveResult result_;

public:

  GoDriveAction(std::string name) :
    as_(nh_, name, boost::bind(&GoDriveAction::executeCB, this, _1), false),
    action_name_(name)
  {
    ROS_INFO_STREAM(action_name_.c_str() << " server is running");
    as_.start();
  }

  ~GoDriveAction(void)
  {
  }

  void executeCB(const action_test::GoDriveGoalConstPtr &goal)
  {

    DO SOMETHING

  }
};


int main ...