Another issue that may occur if IE is used, is that the poll sidebox is not resized after voting and display of the vote results.

To fix this:

In file: /includes/templates/<YOUR TEMPLATE>/sideboxes/tpl_poll_box.php

Around line 69, insert AFTER the following line:

document.getElementById(element_id).innerHTML = http.responseText;

these two lines:

document.getElementById(element_id).style.display="none";
document.getElementById(element_id).style.display="block";

This will force the browser to re-render the DIV element after receiving the AJAX-results.