The way Captivate's pretest questions are currently implemented means they must be at the beginning of a project file, not near the end of the content and cannot come AFTER other quiz slides that report to the quiz. (The next thing you may discover is that the presence of pretest questions in a project also disables the playback bar across the entire project.)
It sounds to me like you may have your course built as a single large Captivate project file. Is that correct? If so, to achieve your goal, you may find it necessary to break it up into multiple project files, one for each module. You can then use either the Aggregator, or for LMS delivered courses, use the Multi-SCORM Packaging tool.
Rod Ward
http://www.infosemantics.com.au/troubleshoot-adobe-captivate