Created a custom msg to support an array of strings but I get thhis warning msg when i use it..

edit

I created a custom msg which is an array or strings. this is my declaration:

    string[] data

However when I use this msg, i get a warning. I dont understand why I get this warning.

   [WARN] [WallTime: 1401683261.952534] Could not process inbound connection: topic types do not match:[std_msgs/String] vs. [beginner_tutorials/StringArray]{'message_definition': 'string data\n\n', 'callerid': '/rostopic_3711_1401673205336', 'tcp_nodelay': '0', 'md5sum': '992ce8a1687cec8c8bd883ec73ca41d1', 'topic': '/tag_history', 'type': 'std_msgs/String'}

Can somebody please tell me how I can get rid of this? THanks

My code where i am using ths StringArray datatype:

#!/usr/bin/env python
import rospy
from std_msgs.msg import String
from beginner_tutorials.msg import StringArray


def callback(data):
    global c
    str=StringArray()
    pub = rospy.Publisher('tag_history',StringArray)
    c.append(data.data)
    if len(c)>3:
       c=c[1:4]    
    str.data=c
    print str
   pub.publish(str)


 def listener():

 rospy.init_node('tag_history', anonymous=True)

 rospy.Subscriber("DA_tags", String, callback)
 rospy.spin()


if __name__ == '__main__':

 global c
 c=[]
 listener()

This is the data i see when i enter "rostopic echo DA_tags"

 uahmed9@uahmed9-Lenovo-IdeaPad-U410-Touch:~$ rostopic echo DA_tags
 data: Query-yn
 ---
 data: Unknown
 ---
 data: Unknown
 ---
 data: Acknowledge
 ---
 data: Unknown
 ---
 data: Unknown
 ---

This is the output for rostopic info DA_tags

uahmed9@uahmed9-Lenovo-IdeaPad-U410-Touch:~$ rostopic info DA_tags
Type: std_msgs/String

Publishers: 
 * /rosjava_tutorial_pubsub/listener (http://127.0.0.1:59178/)

Subscribers: 
 * /tag_history_32168_1401828816089 (http://uahmed9-Lenovo-IdeaPad-U410-Touch:51087/)