On a few occasions when i tried replying to polls after clicking "Submit" a page comes up telling me i voted for this poll already!
Very bizzare. I've never had this problem.
I've also done a quick look on my support site for the forum software we run with little success.
Perhaps try using the the POST REPLY as apposed to to the quick reply box down below?
No that's not it!
It has to do with locking in my vote on poll. When i replied to 2 or 3 polls and clicked "submit" a page would come up telling me my vote had already been registered for that poll!