Microsoft powerpoint Add-In issue

Question

I've created a powerpoint COM add-in by using the VS2005 Shared Add-in template. I managed to deploy the add-in succesfully, but I noticed that once I install the add-in, even after I shut down powerpoint, POWERPNT.EXE proccess remains running (as I can check from the task manager processes panel).

I did some testing and turns out the bug occurs when the following part of the code runs:

using Microsoft.Office.Interop.PowerPoint;

ApplicationClass pptApplication = new ApplicationClass();
Presentation pptPresentation = pptApplication.ActivePresentation;

pptPresentation.SaveAs(pptPresentation.Name,
    Microsoft.Office.Interop.PowerPoint.PpSaveAsFileType.ppSaveAsJPG,
    Microsoft.Office.Core.MsoTriState.msoTrue);

What I have to do to correct that behavior?

Regards.