About the Poll results button

I made a poll today for my forum ... I am wondering if I did something wrong.. It all seemed to be working good as gold until a member clicked on the results button and it froze the poll to everyone in the results position so no one else could vote anymore ... i have since reset it back to zero and its up again looking good, but worried the same thing will happen. Have I missed doing something? Or not checked a box or something that makes that happen?

Regards to you Sarveswara