Page restrictions aren't working Conf 3.3.1 and theme builder

We have upgraded to confluence 3.3.1 recently and installed theme builder 4.1.3. We noticed that page restrictions aren't working i.e, on the page restrictions dialog, we are not able to restrict page to either user or group (ex: type group name and click restrict - nothing happens).

However, when I 'disable' theme builder plugin, page restrictions are working fine. I tried earlier versions of theme builder, but still the same problem. I am wondering if there is a work around for this issue.