read, write Objects via Sockets

 Hi

I have big problem with memory leak (heap size usage). I send object via
Sockets using object input, output stream.
The problem occurs on the client side when i receive an object

public class My implements Serializable{

/** Creates a new instance of My */
public My() {
}

private String newField =
"ewqeqwewqewdsadsadasdsadsadsadsadadsadsadasdsadsadsadasdasdasdasdasdadsadsasddsadasdsadsa";

public String s(){
return this.newField;
}

}

Server side !!!

ServerSocket s = new ServerSocket(1111);
Socket sv = s.accept();

ObjectOutputStream oos = new ObjectOutputStream(sv.getOutputStream());

while(true){

My m = new My();

oos.writeObject(m);
oos.flush();

m=null;

}
clietn side !!

while(true){

My x = (My)oos.readObject();

System.out.println("pdu size:"+x.s());
x = null;
}

The problem is that memory goes up each time i receive My object. Heap
memory goes up and up and gc() cannot clean memory.

But what is the most funny part . When i'm using insted of My class just
simple byte [] array and send via Socket also using object, input output
stream the problem doesn't occure !. But byte array is also serialized by
default .
Profiler in netbeans shows that it gowas up and down - so the way i would
like it to go :D
What may be the cause of this problem ? implementing Serializable or write,
read object methods have some problems ?