Document. Write down dates, times, and conversations. Include the names of anyone who's overheard him. If you can legally tape secretly, do so. There's not much HR can do when it's a he-said, she-said situation, so make sure it's not. There is an HR parlance, if it isn't documented, it didn't happen. So get your documentation, have your proof, name your witnesses. Give them something they can work with.

THEN if they still don't do anything, take your documentation and your tapes to the EEOC.