GetDIBits help!

I'm trying to make a function which takes a bitmap and replaces every src color to des color. However I am having trouble retrieveing the bitmaps bits. My code looks like this so far:

BOOL ReplaceColor(HBITMAP hBitmap, COLORREF clSrcColor, COLORREF clDesColor)
{
	HDC		bitmapDC;
	BITMAP		bitmap;
	unsigned char*	bitmapBits; 

	bitmapDC = CreateCompatibleDC(NULL);
	GetObject(hBitmap, sizeof(BITMAP), &bitmap); 

	BITMAPINFO	bitmapInfo;
	ZeroMemory(&bitmapInfo.bmiHeader, sizeof(BITMAPINFOHEADER));
	bitmapInfo.bmiHeader.biSize		= sizeof(BITMAPINFOHEADER);
	bitmapInfo.bmiHeader.biWidth		= bitmap.bmWidth;
	bitmapInfo.bmiHeader.biHeight		= bitmap.bmHeight;
	bitmapInfo.bmiHeader.biPlanes		= 1;
	bitmapInfo.bmiHeader.biBitCount		= 8;
	bitmapInfo.bmiHeader.biCompression 	= BI_RGB; 

	bitmapBits = new unsigned char[bitmap.bmWidth*bitmap.bmHeight];
	int scanLines = GetDIBits(bitmapDC, hBitmap, 0, bitmap.bmHeight, bitmapBits, &bitmapInfo, DIB_RGB_COLORS);
	if(scanLines == 0)
		return FALSE; 

	return TRUE;
}
 

And it fails, as no scanlines are read. And the problem is not what I fill in the bmiHeader as I know the bitmap is uncompressed and is 8bits per pixel... Any ideas?