Why is Mockito behaving weird with InputStreams?

While debugging I came across something incredibly strange using Mockito 1.10. I was hoping someone could explain the behavior perceived here:

When I run the following, my thread hangs and my test never returns. CPU of the Java process created goes astronomical too!

@Test(expected = IOException.class)
public void mockitoWeirdness() throws IOException {
    final InputStream mis = mock(InputStream.class);
    doThrow(IOException.class).when(mis).read();
    ByteStreams.copy(mis, new ByteArrayOutputStream());
}

When I manually stub this method as follows, the expected IOException is thrown:

@Test(expected = IOException.class)
public void nonMockitoExpected() throws IOException {
    final InputStream mis = new InputStream() {

        @Override
        public int read() throws IOException {
            throw new IOException();
        }
    };
    ByteStreams.copy(mis, new ByteArrayOutputStream());
}

Any help understanding how and why the mockito method is failing would be fantastic.