Problem with my advanced poll

Hi there. I just recently added an Advanced Poll to my growing website, but I am having a small problem. All is fine when the poll is on the page, everything looks good, but when you vote in the poll, the results are shown but at the very top of the webpage there is an odd message.

Warning: Cannot modify header information - headers already sent by.... in /home/darrenha/public_html/polls/poll_cookie.php on line 21

I'm not sure what this means and how to fix that. I am wondering if I need to change my permissions in the poll_cookie file.

I also have a php calendar on that site and that may be somehow conflicting with my poll but I don't know why or how it would be.

This is the link to my page if you want to try the poll out, and vote, and see what happens:

http://www.darrenhayesinteractive.com/music.php

Laurie

Can anyone help me with this?

I voted - no problem, no error message. I guess you fixed it?

Great site!