Problem in drawing transparent bitmap

void CPictureManager::TransparentBitmap(CDC* pDC,CBitmap *pBitmap, CRect render,int iSrcWidth,int iSrcHeight,COLORREF clrpTransColor)
{
	CDC dcTemp;
	dcTemp.CreateCompatibleDC(pDC);
	CBitmap* bmTemp = dcTemp.SelectObject(pBitmap);
	BITMAP bm;
	pBitmap->GetBitmap(&bm);
	POINT ptSize;
	ptSize.x = bm.bmWidth;		// Get width of bitmap
	ptSize.y = bm.bmHeight;		// Get height of bitmap
	dcTemp.DPtoLP(&ptSize, 1);	// Convert from device to logical points

	// Create some DCs to hold temporary data.
	CDC dcMem;
	dcMem.CreateCompatibleDC(pDC);
	CDC dcBack;
	dcBack.CreateCompatibleDC(pDC);
	CDC dcObject;
	dcObject.CreateCompatibleDC(pDC);
	CDC dcSave;
	dcSave.CreateCompatibleDC(pDC);

	// Monochrome DC
	CBitmap bmAndBack;
	bmAndBack.CreateBitmap(ptSize.x,ptSize.y,1,1,NULL);

	// Monochrome DC
	CBitmap bmAndObject;
	bmAndObject.CreateBitmap(ptSize.x,ptSize.y,1,1,NULL);

	// Color DCs
	CBitmap bmAndMem;
	bmAndMem.CreateCompatibleBitmap(pDC,ptSize.x,ptSize.y);
	CBitmap bmSave;
	bmSave.CreateCompatibleBitmap(pDC,ptSize.x,ptSize.y);

	// Each DC must select a bitmap object to store pixel data.
	CBitmap* bmBackOld = (CBitmap*)dcBack.SelectObject(&bmAndBack);
	CBitmap* bmObjectOld = (CBitmap*)dcObject.SelectObject(&bmAndObject);
	CBitmap* bmMemOld = (CBitmap*)dcMem.SelectObject(&bmAndMem);
	CBitmap* bmSaveOld = (CBitmap*)dcSave.SelectObject(&bmSave);

	// Set proper mapping mode.
	dcTemp.SetMapMode(pDC->GetMapMode());

	// Save the bitmap sent here, because it will be overwritten.
	dcSave.BitBlt(0,0,ptSize.x,ptSize.y,&dcTemp,0,0,SRCCOPY);

	// Set the background color of the source DC to the color.
	// contained in the parts of the bitmap that should be transparent
	COLORREF cColor;
	cColor = dcTemp.SetBkColor(clrpTransColor);

	// Create the object mask for the bitmap by performing a BitBlt
	// from the source bitmap to a monochrome bitmap.
	dcObject.BitBlt(0,0,ptSize.x,ptSize.y,&dcTemp,0,0,SRCCOPY);

	// Set the background color of the source DC back to the original
	// color.
	dcTemp.SetBkColor(cColor);

	// Create the inverse of the object mask.
	dcBack.BitBlt(0,0,ptSize.x,ptSize.y,&dcObject,0,0,NOTSRCCOPY);

	// Copy the background of the main DC to the destination.
	dcMem.BitBlt(0,0,ptSize.x,ptSize.y,pDC,render.left,render.top,SRCCOPY);

	// Mask out the places where the bitmap will be placed.
	dcMem.BitBlt(0,0,ptSize.x,ptSize.y,&dcObject,0,0,SRCAND);

	// Mask out the transparent colored pixels on the bitmap.
	dcTemp.BitBlt(0,0,ptSize.x,ptSize.y,&dcBack,0,0,SRCAND);

	// XOR the bitmap with the background on the destination DC.
	dcMem.BitBlt(0,0,ptSize.x,ptSize.y,&dcTemp,0,0,SRCPAINT);

	// Copy the destination to the screen.
	pDC->StretchBlt(render.left,render.top,render.Width(),render.Height(),&dcMem,0,0,iSrcWidth,iSrcHeight,SRCCOPY);

	// Restore the original bitmap.
	dcTemp.BitBlt(0,0,ptSize.x,ptSize.y,&dcSave,0,0,SRCCOPY);

	// Delete the memory bitmaps.
	dcBack.SelectObject(bmBackOld);
	dcObject.SelectObject(bmObjectOld);
	dcMem.SelectObject(bmMemOld);
	dcSave.SelectObject(bmSaveOld);
	dcTemp.SelectObject(bmTemp);
}