// Decode file to buffer
// Hardcoded for 16-bit stereo
void decode(OggVorbis_File *pFile, void *pBuffer)
{
	int nLength = ov_pcm_total(pFile, -1) * 4;

	int nTotalRead = 0;
	int current_section;

	while (nLength > 0)
	{
		int nBytesRead = ov_read(pFile, ((char *)pBuffer) + nTotalRead, 
nBytesToRead, 0, 2, 1, &current_section);

		if (nBytesRead > 0)
		{
			nTotalRead += nBytesRead;
			nLength -= nBytesRead;
		}
		else if (nBytesRead == 0)
		{
			OutputDebugString("EOF reached\n");
			return;
		}
		else
		{
			OutputDebugString("Error in stream detected\n");
		}
	}

	// We never get here EOF is always reached first
	OutputDebugString("It worked\n");
}

This was done using the 1.0 win32 sdk (using static linked release libs) and 
the files were encoded with oggdropXPd v1.1 (Compiled 20020719).

To make it work as expected I needed to change the first line to read:

int nLength = (ov_pcm_total(pFile, -1) - 1) * 4;