谷歌云消息注册(serive不可用错误)

我在尝试向GCM注册时遇到此错误。我的AVD目标是Android 4.2.2，API级别是17。请在下面找到堆栈跟踪。

07-11 14:17:58.577: W/System.err(800): java.io.IOException: SERVICE_NOT_AVAILABLE
07-11 14:17:58.577: W/System.err(800):  at com.google.android.gms.gcm.GoogleCloudMessaging.register(Unknown Source)
07-11 14:17:58.577: W/System.err(800):  at com.exp.code.utils.AsyncRequestWeb.doInBackground(AsyncRequestWeb.java:99)
07-11 14:17:58.577: W/System.err(800):  at com.exp.code.utils.AsyncRequestWeb.doInBackground(AsyncRequestWeb.java:1)
07-11 14:17:58.577: W/System.err(800):  at android.os.AsyncTask$2.call(AsyncTask.java:287)
07-11 14:17:58.577: W/System.err(800):  at java.util.concurrent.FutureTask.run(FutureTask.java:234)
07-11 14:17:58.590: W/System.err(800):  at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
07-11 14:17:58.590: W/System.err(800):  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
07-11 14:17:58.598: W/System.err(800):  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
07-11 14:17:58.609: W/System.err(800):  at java.lang.Thread.run(Thread.java:856)

有什么建议吗？我在这个问题上纠结了很长时间。是防火墙阻塞端口的问题还是代码的问题。。。。