WMP Mute when UiMode is None

I have a problem when trying to mute sound from my Playlist when in UiMode "none".

The code

CWMPPlaylistCollection playlistCollection = m_player.GetPlaylistCollection();
CWMPPlaylist playList = playlistCollection.newPlaylist(_T("MyList"));

playList.appendItem(m_player.newMedia(_T("V:\\Videos\\1.mp4")));
playList.appendItem(m_player.newMedia(_T("V:\\Videos\\2.mp4")));
playList.appendItem(m_player.newMedia(_T("V:\\Videos\\3.mp4")));

m_player.SetUiMode(_T("none"));
m_player.SetWindowlessVideo(TRUE);
m_player.SetStretchToFit(TRUE);
m_player.SetEnableContextMenu(FALSE);
BOOL bIsMute = m_player.GetSettings().GetIsAvailable(_T("Mute"));
if (bIsMute)
	m_player.GetSettings().SetMute(TRUE);

m_player.GetControls().play();

works well for the first video, but the sound is turned on when the second video automatically starts?

I have noticed, that if I select UiMode "full" or "mini" it works, then I can also see the mute button?

Any ideas what is wrong?

-cpede