Being quoted for an incorrect statement
Contact the author first.  Assume the best, that their memory is faulty, and suggest alternative text in a friendly manner.  If you do not get a response, contact the editor of the journal they have submitted to.

Ultimately though a lot of people get misquoted, and a lot of publications get misunderstood &amp; cited inappropriately.  If it's really a big deal you might get a publication out of contradicting it, but otherwise just be glad that people think you are important enough to mention.  It's better than not being given credit for your own ideas!