Or at the very least, don't allow people to vote on their own posts. I believe it degrades the IPVM experience and downgrades IPVM's discussion groups to the level of LinkedIn Discussion Groups and Yahoo! Message Boards.
In my opinion, if someone adamently agrees with a post or poster's point of view, I would get much more out of a brief post of agreement or additional data points that enhance the original post than a "thumbs up" or "thumbs down".