File Observer not working from intent service

I found a great class to extend the abstract class File Observer ...

import android.os.FileObserver;
import java.io.DataInputStream; 
import java.io.DataOutputStream; 
import java.io.File; 
import java.io.FileInputStream; 
import java.io.IOException; 
import java.net.HttpURLConnection; 
import java.net.MalformedURLException; 
import java.net.URL; 
import android.util.Log;

public class FileSync extends FileObserver {
public String absolutePath;
public String uid;

public FileSync(String path, String uidd) {
    super(path, FileObserver.ALL_EVENTS);
    absolutePath = path;
    uid = uidd;
}
@Override
public void onEvent(int event, String path) {
    if (path == null) { //path is the name of the file... I think its absolute
        return;
    }
    //a new file or subdirectory was created under the monitored directory
    if ((FileObserver.CREATE & event)!=0) { 
        doFileUpload(path, uid);
    }
    //a file or directory was opened
    if ((FileObserver.OPEN & event)!=0) {
        //TODO Nothing... yet
    }
    //data was read from a file
    if ((FileObserver.ACCESS & event)!=0) {
        //TODO Nothing... yet
    }
    //data was written to a file
    if ((FileObserver.MODIFY & event)!=0) {
        doFileUpload(path,uid);
    }
    //someone has a file or directory open read-only, and closed it
    if ((FileObserver.CLOSE_NOWRITE & event)!=0) {
        //TODO Nothing... yet
    }
    //someone has a file or directory open for writing, and closed it 
    if ((FileObserver.CLOSE_WRITE & event)!=0) {
        doFileUpload(path,uid);
    }
    //[todo: consider combine this one with one below]
    //a file was deleted from the monitored directory
    if ((FileObserver.DELETE & event)!=0) {
        //TODO Remove file from the server
    }
    //the monitored file or directory was deleted, monitoring effectively stops
    if ((FileObserver.DELETE_SELF & event)!=0) {
        //TODO Toast an error, recreate the folder, resync and restart monitoring
    }
    //a file or subdirectory was moved from the monitored directory
    if ((FileObserver.MOVED_FROM & event)!=0) {
        //TODO Delete from the server
    }
    //a file or subdirectory was moved to the monitored directory
    if ((FileObserver.MOVED_TO & event)!=0) {
        doFileUpload(path,uid);
    }
    //the monitored file or directory was moved; monitoring continues
    if ((FileObserver.MOVE_SELF & event)!=0) {
        //TODO Recreate the folder and show toast
    }
    //Metadata (permissions, owner, timestamp) was changed explicitly
    if ((FileObserver.ATTRIB & event)!=0) {
        //TODO Nothing... Yet
    }
}

I create three of these observers in onCreate IntentService as follows:

new File("/sdcard/Docs/").mkdir();
FileSync files = new FileSync("/sdcard/Docs/",uid);
FileSync pictures = new FileSync(Environment.DIRECTORY_PICTURES,uid);
FileSync music = new FileSync(Environment.DIRECTORY_MUSIC,uid);
files.startWatching();
pictures.startWatching();
music.startWatching();

Not only observers do not work, but the mkdir function does not work.

Any ideas? Thank!