If anyone in your group is on Moderation, they cannot vote in the poll.?
The only members who can vote in a poll are those who have no restrictions in posting
Sorry, but that is simply not true. I didn't think it was, but I have done a quick test on Shal's test group and moderated members are perfectly able to vote in a poll.
The "major" hurdle to getting a properly representative result from a poll is that members cannot vote by email; voting can only be carried out via the web UI, and of course to use that members have to be logged in. As is generally recognised individual groups have a (large?) number of members who either cannot or will not log in to the web UI so their opinion on any polled question simply doesn't get included.