Stopping two threads through a volatile variable

Hello,
I have a client application receiving messages from a server. As the code is now, a thread is started twice. The thread class is inheriting an isAlive boolean variable used in the while loop in the run method (where the specific processing is performed). When it's time to kill the thread, the isAlive variable is set to false, but at least one of the threads keeps running. From what I understood [how volatile variables work|http://www.javaperformancetuning.com/news/qotm030.shtml] , this should not be happening - one call to the kill() method should make both threads stop, as they are using a synchronized variable value. What am I doing wrong?
The following code is reduced to the relevant parts (hopefully):
// this block is executed within a method that processes received messages. There is always two OPT messages received (but with different further parameters), so the thread is started twice.
if ( receivedMessage == OPT ) {
    thread = new Thread() // sets isAlive to true
    thread.start()
// run method
...public void run() {
       while(isAlive) {
          ... do stuff
// kill method in the thread superclass
public void kill() {
    isAlive = false;
// killing the thread
thread.kill();

... [how volatile variables work|http://www.javaperformancetuning.com/news/qotm030.shtml] ...
hmm are you sure that stuff at above link is up-to-date?
I ask because it is dated 2003 but volatile in Java 5 and newer conforms to specification that was finalized in 2004 ([JSR 133 Java Memory Model|http://www.jcp.org/en/jsr/detail?id=133|jcp])

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Stopping two threads through a volatile variable

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