Android - onBackPressed() not working

I have an application building against Android 2.1 and I want to override the back button.

I have followed the example here:

http://android-developers.blogspot.com/2009_12_01_archive.html

And my code is as follows:

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event)  {
        if (Integer.parseInt(android.os.Build.VERSION.SDK) < 5
                && keyCode == KeyEvent.KEYCODE_BACK
                && event.getRepeatCount() == 0) {
            Log.d("CDA", "onKeyDown Called");
            onBackPressed();
        }

        return true;
    }

    @Override
    public void onBackPressed() {
    Log.d("CDA", "onBackPressed Called");
        Intent setIntent = new Intent(Intent.ACTION_MAIN);
        setIntent.addCategory(Intent.CATEGORY_HOME);
        setIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        startActivity(setIntent); 

        return;
    }   

It works on pre 2.x devices but doesn't work on a Hero with 2.1 update-1 and a Nexus One with 2.2.

Is there somwthing I am missing from the example? Or can anyone point out why it isn't working?

I dont even get the button pressed in the logcat.

Are you using onKeyUp()?

Use just onKeyDown() in Android 1.x or onBackPressed() in Android 2.x

Some quick searching suggests you should place the Back intercept during onKeyUp(): http://developer.android.com/sdk/android-2.0.html. It's worth a try. The following code is directly from the site:

public boolean onKeyDown(int keyCode, KeyEvent event) {
    if (keyCode == KeyEvent.KEYCODE_BACK
            && event.getRepeatCount() == 0) {
        event.startTracking();
        return true;
    }
    return super.onKeyDown(keyCode, event);
}

public boolean onKeyUp(int keyCode, KeyEvent event) {
    if (keyCode == KeyEvent.KEYCODE_BACK && event.isTracking()
            && !event.isCanceled()) {
        // *** DO ACTION HERE ***
        return true;
    }
    return super.onKeyUp(keyCode, event);
}

You should call parent constructors.

In onKeyDown() method call

super.onKeyDown();

and in onBackPressed()

super.onBackPressed();