You may see the following error message when opening a presentation in PowerPoint:
Articulate Presenter has detected that there are presentations open which were loaded before this add-in was loaded.
To avoid loss of Articulate Presenter project data, please unload this add-in first then close all presentation thereafter load this add-in again.
This issue was corrected in Update 6 for Presenter '09. To take advantage of the new features and fixes, download and install the latest version from the link in your product confirmation email, or get it here.