Update the framework files to the latest version and this issue should be fixed. I think the two files that need to be updated are:
webassist/framework/javascript/ajax.js
and
webassist/framework/ajax_wrapper.php
I've attached the newest versions for you. Recent updates to the apache mod_security module make some servers block the ajax communication thinking it is malicious. The latest versions have been updated to get around the problem and pass security checks.