First, undo any changes you made copying files from xoopspoll module extras directory. You should go back to the versions of those files as distributed with newbb.
Then, in modules/newbb/votepolls.php change line 73 that looks like this:
$optionId = !XoopsRequest::getInt('option_id', 0, 'POST');
and remove the ! sign in front of XoopsRequest, to look like this:
$optionId = XoopsRequest::getInt('option_id', 0, 'POST');
This should enable poll votes. There will still be issues with recording votes in multliple option polls, and we will address those in a patch soon.