We recently switched from using powerpoint.dll to slides.dll. Now we are experiencing a problem we have never seen before. When doing slide show of generated slides in Powerpoint 2003, some slides are missing content. But the content does appear in edit mode. And after saving the slides (without making any changes) and re-opening the saved as file, the slide show had no issues. We even tried to use powerpoint.dll to merge the same set of slides and did not see the same problem as using slides.dll to merge. Please let us know what could be the problem and if you need additional information.
Can you please attach some sample files, so that we could reproduce the problem and fix it?