LoadMappedBitmap

I have not been successful in converting from using LoadBitmap to LoadMappedBitmap. I am trying to overcome a problem with the button face in my toolbar bitmap which was created in an image editing tool to be the correct color. Using LoadMappedBitmap causes some terrible problem (it takes for ever for the application to load and the toolbar buttons are totally clobbered with noise). This is the relevant code. What am I doing wrong?

Thanks, Bob

COLORMAP clrMap[] =
{ RGB(192,192,192), ::GetSysColor(COLOR_APPWORKSPACE),
RGB(207,200,207), ::GetSysColor(COLOR_3DFACE),
RGB(255,255,255), ::GetSysColor(COLOR_3DHIGHLIGHT),
RGB(0,0,0), ::GetSysColor(COLOR_3DSHADOW) };

if (!m_TBNav.Create(this, WS_CHILD | WS_VISIBLE | CBRS_TOP
| CBRS_TOOLTIPS | CBRS_FLYBY | CBRS_SIZE_DYNAMIC, IDR_TBNAV))
{
TRACE0("Failed to create toolbar\n");
return -1; // fail to create
}

m_NavBitmap.LoadMappedBitmap(IDB_NAVIGATION, 0, (COLORMAP*)&clrMap, 3);
// should this be 3 or 4 for map size ?? -- using 4 doesn't solve problem

m_TBNav.SetBitmap((HBITMAP)(m_NavBitmap));
m_TBNav.SetButtons(NavIDs, sizeof(NavIDs)/sizeof(UINT));