I know the plugin saves the answers and works. In order to get the problem resolved, you might want to list all the specifics about your current wordpress configuration in order to get this resolved. The problem might be a configuration that has not been tested.
What OS are you using? What version of WordPress are you using? What java and php version are you running? What plugins and wordpress theme are you using? All these questions answered can help pin point where the problem is. To do some debugging you might want to turn off plugins and see if that makes a difference, and changing the theme