I ran into a problem today when I tried to vote to close a question. The question had been perviously closed and I had voted for that closing, but now it had been reopened by a moderator. I thought it should still be closed since the only problem was a typo in the code. I found I could not make a vote to close because "You have already voted to close this question". Is this the policy? Can one not vote to close a reopened question if one has voted in the first closing?