I could be wrong, but I believe that DS did not play in international markets during its original US run, so a title such as HOUSE OF DARK SHADOWS would have little marquee value oversees. On the other hand, a title such as LIPS OF BLOOD implies all sorts of eroticism and violence and thus is more intriguing. The same goes for the French title, LA FIANCEE DU VAMPIRE.
Also, literal translations can be confusing. I once put HODS into an online translation engine, translated it into Chinese, and then translated the Chinese back into English. HOUSE OF DARK SHADOWS became DARK SHADOW OF THE LEGISLATIVE BODY! <lol>
Regards,
John