We have investigated the problem and it looks to be related to FCK editor. You can use TinyMCE editor what comes as a standard in Joomla! or even create questions without an editor.
FCK editor has several bugs and it's impossible for us to guarantee that our extensions will work with all third-party extensions. But we really try to make it work with the most major extestions.
Here is the
problem. Once it is fixed we will work on providing fix for FCK editor. For now could you please use other editors like standard Joomla!'s TinyMCE.
Regards,
ARI Soft