interviewing then hearing from headhunter

[Anonymous]

I've interviewed a couple of times for a job over the last couple of months. Things stalled and I assume they aren't interested. Earlier this week, I was contacted by a headhunter to discuss a position that - at least in the general terms he described - sounds a lot like the job I've already interviewed for. Headhunter didn't reveal specific firm name, for example. I am supposed to speak with the headhunter next week to get more details. If it turns out to be the same job, what would you recommend? Do I say nothing and "ride it out?" Do I reveal that I have already interviewed?
Obviously, I don't want to waste anyone's time and I don't want to have the headhunter contact the firm (and make me a less desirable candidate b/c firm would need to pay headhunter fee). But I also wonder if having "another iron in the fire" outweighs these concerns. Any thoughts are appreciated.

[Anonymous]

Typically, if you have already contacted the employer on your own, the headhunter would not be eligible to get their fee. And besides, what else do you think a headhunter could do for you now that you have already interviewed? I would tell them you already interviewed at company X for a similar position, and then the headhunter could tell you if it's the same job or something else.

[Anonymous]

What about when the job is in a different division of the same large firm. The first contact with the company was essentially an informational interview in one part of the firm (which didn't progress but did involve giving the people you met with copies of my resume). Now, the recruiter is looking for someone to fill an actual real job in a different part of the company.
I've disclosed this to the recruiter, but want to make sure I'm not doing something wrong or unethical. Do I need to contact the people I info interviewed with (even though they haven't expressed interest)? Am I now prohibited from applying to other jobs in this company (even through a recruiter)? Thx