It would be interesting to know which two dictionaries you've referred to. The OED is generally regarded as the bible of English spelling and pronunciation. Its editors seem to be happy with the 'long a' sound (i.e. 'haynus').
Perhaps you've consulted an American dictionary, such as Webster's? If so, you might as well have looked at a dictionary of French, German or Serbo-Croat. I don't know what language they speak on the other side of the Atlantic, but it certainly isn't English!