@browncoat - The annoying thing is that you are at the whim of the interviewer, particularly if there is only one of them, and asking the wrong question can quickly backfire, but it's impossible to know beforehand what the wrong question might be.
If you ask questions that are too basic, they might wonder if you did any research before coming to the interview. If you ask questions that are too complicated, they might get frazzled and annoyed with you for wasting their time.
I would take my cue from the interviewer as much as possible. If they touch on a subject, ask for clarification if you need to. And if there are any deal breakers, then ask about them as well.