Here is the situation.
A question seemed interesting at first because I was really wondering what the community would answer. A couple minutes later I realized the question does not really fit the guidelines for questions on Programmers.
I wanted to undo my upvote by clicking on the down arrow, but a popup told me I could not do it because I just upvoted the question 13 minutes ago and I cannot do anything until the question is edited.
Why cannot I undo my vote?
Note: I really wanted to flag the question but I thought it would look odd that I upvoted and then I flagged.