Do you have sealant over and around the half moon seals as they usually leak? If it's indeed leaking from the cam seals and you have replaced them there is one thing to try aswell. There is a circlip over the cam bearings which has ~5 mm opening on it and it sits in a groove. I rotated the circlip so that the opening is upwards, instead of any other way. Don't know if it makes difference but I did this.