IE9 throws js errors, and won't allow voting when the voting taglib is brought in via ajax. Works in chrome, safari, and firefox. Please see the sample portlet attached. Simply add this portlet to a page, and watch IE9 error out in the developer tools window (console tab). Try to vote, notice you can't in IE9.
Steps to reproduce
1) Deploy attached plugin
2) Using ie9 - try to vote (you can't)- see console errors on developer tools
3) Works in chrome and firefox
Reproduced in trunk.