Yes, I have it set to 3. Perhaps this is the reason. I was thinking when I set up the poll that that meant having 3 choices. The more I thought about it, the more it makes sense that this is the reason for this behavior. Next time I know to only allow 1 response (if applicable). It is a bit confusing however when setting up a poll, because there are no fields visible to enter choices until you tab from the field you just filled. The 'maximum selected responses' is directly below those fields, so I always think it is to create more fields/choices.