The default code uses require_once() to include the security question. That will only add it once... I changed it to require() and that worked to show the question, but it shows the same question twice which looked odd to me.
So I updated the include file for the security question to allow you to set a version and have more than one version on a page. Then I updated both of your plugins to set the different versions and refer to the correct session variables.
It should be working now. Please download your plugin files and the wavt_captchasecurityquestion.php file to make sure you have my updates.