PowerPoint 97 vs 2000 incompatibilities
Though PowerPoint 97 and 2000 share the same file format, they don't do everything exactly the same. Some new features added in PowerPoint 2000 aren't supported by PowerPoint 97. We describe these in more detail in PowerPoint 2000 features not supported in PowerPoint 97
There are a few other differences as well:
If you select text and apply underlining in PowerPoint 97, the words themselves will be underlined but not the spaces and tabs between them. When you open this same presentation in PowerPoint 2000, everything, spaces and tabs included, will be underlined. New text you create and underline in PowerPoint 2000 will also have spaces and tabs underlined.
Hyperlinks in groups
If you group multiple objects that have hyperlink action settings in PPT2000, the links all work correctly when you view the presentation as a screen show. When you view the same presentation as a screenshow in PowerPoint 97 or the Viewer, the links don't work. Links within groups don't work in PPT97 or the viewer.
The "hide after mouseclick" feature works differently in the two versions, and the way the animations are timed has changed.