Transition animations that are compatible with the PowerPoint viewer include:

Blinds
Boxes
Checkerboards
Covers
Cuts
Dissolves
Fades
Random Bars
Splits
Strips
Uncovers
Wipes

Other animation effects that are compatible with the viewer include:
Fly-ins
Flash Once
Type Writer
Appear

To ensure that you use only animations that are compatible with the PowerPoint viewer, follow these steps:

On the Tools menu, click Options.

In the Options dialog box, click the Edit tab.

Under Disable new features, click to select the New animation effects check box, and then click OK.

NOTE: Now when you click Custom Animation on the Slide Show menu, a Custom Animation dialog box appears instead of the Custom Animation task pane. The animations listed in the Custom Animation dialog box are all compatible with PowerPoint 97 and PowerPoint 2000.