At the moment it seems that anything posted in the surveys/polls part of the forum can’t be edited, I’m guessing this was done to prevent tempering with the results by changing the vote option ‘labels’ around after the votes come in.
However, we’re already stuck with the 10 minutes limit… so it would be hard to do any serious tempering with the results, hard to imagine that the majority of votes would come within the 10 minutes after posting it.
Problem now is that you can’t edit normal replies either, you reply… forget something, want to edit your post (within the 10m limit)… and it’s not possible.