sabahat on "[Plugin: WP Voting] Error for some posts"

Hi,

I have a few users who are complaining that they get this error when they vote:

Error: Voting! Please try again later. votedvote

Can anyone tell me what this means? It is only happening on one post: http://www.indireads.com/let-me-go/

http://wordpress.org/extend/plugins/wp-voting/