Nope, no extra middle step. A couple of rather far-fetched conjectures:

1. You weren't maybe trying to put polls in a post rather than a comment? The markup is different in the two cases, and so far as I know there's no way to put polls in posts.

2. Is it possible that you have some sort of web browser extension that messes with your comment text somehow? (Semi-relevant anecdote: I wrote myself a trivial Greasemonkey script that identifies portions of text that are likely to be rot13-ed and provides a mouseover tooltip for each such chunk that shows the result of rot13-ing it; but because I was sloppy, it sometimes does its thing to material other than actual text, and from time to time that's corrupted my comments on LW. It's easy to imagine something of the sort that happens to mess up LW polls in comments.)