Just in case you haven’t noticed already Adobe recently released a patch for Adobe Captivate 4.
This update contains fixes for a variety of issues and will greatly improve the Audio part of Captivate 4. In order to get the update you open up Captivate 4 and then the “Help” menu and “Updates”. This currently runs through Adobe Updater, which is bad news for the people behind a restrictive corporate firewall.
As far as I know Adobe hasn’t released the patch for direct download yet, but once they do I will post a link to it here.
You can read more about the details of the patch here: http://blogs.adobe.com/captivate/2009/05/captvate_4_patch_update.html