Every forum/message board I've joined didn't allow it, it was called spamming ... so yeah, it annoys me a lot when people do it here. I mean if it's to bump a thread or if you post it after some days it's fine, but otherwise ...
I do it sometimes though I was surprised at first that it's allowed here, like someone else said, every forum I've ever been on at least "discourages" it if they don't outright hand you WPs for it. I do it sometimes if I'm quoting someone after the fact or making another point, but usually it happens because someone else didn't post anything inbetween rather than me trying to post multiple times.
