Android AIDL bindService同步问题

大家好！目前正忙于一个项目，需要用到AIDL技术，遇到了bindService同步的问题，请教高手帮助解决！
问题如下：
有两个应用程序安装在同一个手机上，分为客户端（Client)和服务端(Server),Client通过AIDL去调用Server中的方法并且获得返回的数据，代码如下：
1.Server端
//IService.aidl
package com.demo.aidl;
interface IService{
boolean appRegist(int appid,in String appName);
}
//RemoteService.java
public class RemoteService extends Service {

@Override
public IBinder onBind(Intent intent) {
return stub;
}

private IService.Stub stub=new Stub() {
@Override
public boolean appRegist(int appid, String appName) throws RemoteException {
//应用程序注册(代码省略),直接返回true
//.....
//.....
return true;
}
};

}

2.Client端
public class ClientActivity extends Activity {

private Button appRegist;
private IService iservice;
private boolean result;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

appRegist=(Button) findViewById(R.id.regist);
appRegist.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Intent intent=new Intent("com.demo.aidl.START_SERVICE");
bindService(intent, regConn, BIND_AUTO_CREATE);

//输出注册结果
System.out.println(result);
}
});
}

private ServiceConnection regConn=new ServiceConnection() {

@Override
public void onServiceDisconnected(ComponentName name) {
iservice=null;
}

@Override
public void onServiceConnected(ComponentName name, IBinder service) {
iservice=IService.Stub.asInterface(service);
try {
result=iservice.appRegist(100, "app1");
} catch (RemoteException e) {
e.printStackTrace();
}finally{
unbindService(this);
}
}
};
}

问题是为什么每当第一次点击app regist按钮的时候，输出的结果是false，第一次之后的都是true？
是不是bindService(intent, regConn, BIND_AUTO_CREATE)和ClientActivity不是同步执行的？怎么解决？？？