ListenableFuture behavior seems to be "broken" when executed from Powermock test

Question

Based on guava-libraries example, I am using ListenableFuture.

I am using:
java 1.6
JDeveloper 11.1.1.6.0
guava-13.0.1.jar
junit-4.5.jar
easymock-3.1.jar
powermock-easymock-1.4.12-full.jar

I am trying to ensure that method under test is called in async mode.

My Manager.java code is:

    ...

    public synchronized void   refreshAsync(final String id) {
    m_Log.entry(id);

    ListeningExecutorService service =
        MoreExecutors.listeningDecorator(Executors.newCachedThreadPool());

    ListenableFuture<Details> getDetailsTask =
        service.submit(new Callable<Details>() {
            @Override
            public Details call() {
                System.out.println(Thread.currentThread().toString());
                return MyCacheManager.getDetails(id);
            }
        });

    Futures.addCallback(getDetailsTask ,
                        new FutureCallback<Details>() {
            // we want this handler to run immediately after we push the big red button!

            public void onSuccess(Details details) {
                System.out.println("Success");
                //TODO: publish event
            }

            public void onFailure(Throwable thrown) {
                System.out.println("Failed");
                //TODO: log
            }
        });

    service.shutdown();

    m_Log.exit("done async");
}

...

My test is:

    @RunWith(PowerMockRunner.class)
    @PrepareForTest( { Manager.class,  MyCacheManager.class, TWResourceManager.class, Logger.class })
    public class DetailsTests {
    {

        ...

        @Test (timeout = 4000) 
        public void refreshAsync_RequestedInAsyncMode_NoWaitForComplete() throws Exception {

            // Creating nice mock - because we are not caring about methods call order
            mockStatic(MyCacheManager.class);

            // Setup
            final int operationTimeMilis = 5000;
            expect(MyCacheManager.getDetails(anyObject(String.class))).andStubAnswer(new IAnswer<Details>() {
                    public Details answer() {
                        try {
                            System.out.println("start waiting 5 sec");
                            System.out.println(Thread.currentThread().toString());
                            Thread.sleep(operationTimeMilis);
                            System.out.println("finished waiting 5 sec");
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
                        return Details.getEmpty();
                    }
                });

            replay(MyCacheManager.class);

            replayAll();

            ISchemaActionsContract controller = new TWManager();
            controller.refreshSchemaDetailsAsync("schema_id");

            // We need not to verify mocks, since all we are testing is timeout
            // verifyAll();
        }
    }

When I am running / debugging the test - it is always failed on timeout. It seems that mocked method "MyCacheManager.getDetails" is called in "sync" mode.

But when I am calling same function from regular code / debug - it is running in async mode (I put Thread.sleep(10000) into MyCacheManager.getDetails method, and Manager.refreshAsync method is exited without waiting / be blocked.

Also, If I am changing the method to use regular FutureTask, test pass as expected.

        ...

        Object res = null;
        FutureTask task = new FutureTask(new Runnable() {
                @Override
                public void run() {
                    MyCacheManager.getDetails(id);
                }
            }, res);            

        m_Log.debug("async mode - send request and do not wait for answer.");

        Executors.newCachedThreadPool().submit(task);

Any idea will be more then welcome! :)
Thanks!