That's interesting... I've just been back, and now they think I'm 100% woman.

So either they've worked out a much better method for analysing gender in the intervening four and a half hours, or the results are entirely random. Unless they logged the fact that I'd used the poll to tell them they were wrong, which would give them 100% certainty about the correct answer?

I'd be interested to know if you got the same answer on a later visit.