Fix error in Normalize

src/ITASampleFrame.cpp

@@ -583,7 +583,7 @@ float ITASampleFrame::Normalize()
 	findPeak( &c, &s );
 	float fP = m_vChannels[ c ][ s ];
 	for( int i = 0; i < m_iChannels; i++ )
-		m_vChannels[ i ].div_scalar( fP );
+		m_vChannels[ i ].div_scalar( std::abs(fP) );
 
 	return fP;
 }