Listing windows titles in JNA on Windows 8

Question

I have the following interface :

public interface User32 extends W32APIOptions {

    User32 instance = (User32) Native.loadLibrary("user32", User32.class,
        DEFAULT_OPTIONS);

    boolean EnumWindows(WNDENUMPROC lpEnumFunc, Pointer arg);
    void GetWindowText(int h, StringBuilder s, int nMaxCount);

}

I'm trying to list all the titles of the windows that are currently visible:

final User32 user32 = User32.instance;

user32.EnumWindows(new WNDENUMPROC() {
    @Override
    public boolean callback(HWND hWnd, Pointer data) {
        LOG.debug("callback {}", hWnd);
        byte[] windowText = new byte[512];
        user32.GetWindowTextA(hWnd, windowText, 512);
        String wText = Native.toString(windowText);
        LOG.debug("FOUND! {} {}", hWnd, wText);
        return true;
    }
}, null);

This code works fine on Windows 7 (Apache v6.0, jre6), and I have all the windows listed.

But the same war doesn't work on Windows 8 (Apache v6.0, jre6). I get some weired titles ("theAwtToolkitWindow", "internel window", "Wmi provider host",...) but never the windows that I'm actually looking for.

Any idea why, and how to fix it ?

--== EDIT ==--

Found here: http://msdn.microsoft.com/en-us/library/windows/desktop/ms633497%28v=vs.85%29.aspx

Note  For Windows 8 and later, 
EnumWindows enumerates only top-level windows of desktop apps.

So I guess I'll need to to go to lower-level windows.. but how ?

--== EDIT ==--

I tried to go deeper:

user32.EnumWindows(new MyWNDENUMPROC(0, 3), null);

public class MyWNDENUMPROC implements WNDENUMPROC {

    public int level = 0;

    public int maxLevel;

    public MyWNDENUMPROC(int level, int maxLevel) {
        this.level = level;
        this.maxLevel = maxLevel;
    }

    @Override
    public boolean callback(HWND hWnd, Pointer data) {

        if (maxLevel < level) { //Max level reached..
            return false;
        }
        // Enu les child windows:
        user32.EnumChildWindows(hWnd, new MyWNDENUMPROC(level + 1, maxLevel), null);

        byte[] windowText = new byte[512];
        user32.GetWindowTextA(hWnd, windowText, 512);
        String wText = Native.toString(windowText);
        if (wText != null && wText.length() > 0) {
            LOG.debug("level {} wText {}", level, wText);
        }
        return true;
    }

}

In Windows 7 it goes indeed to deepesr levels, But in windows 8 it stays as level 0.