Help with Powerpoint Compatibility Issue!!

[creative1]

I've created a (beautiful) PP presentation for my client - using OfficeX Powerpoint. When I tested it on my PC, however, many of the transitions, etc. were lost (i.e. fade in became ugly black lines in transition). I thought I'd found the solution with MS Office Powerpoint Viewer - not perfect, but better. However, when I had my client download the Viewer she said it didn't give her better results.
What's the solution? Help!!
Gin

[Jam]

Try saving it as an older version 2000 or 95 if you can.
Alternatively as a PowerPoint Show (PPS)

[Jam]

How big is the file?
Keep an original but try saving on with a Reduced image size/resolution
It may be that the machine can't run such a big file

[Jam]

Do you have Acrobat professional?
You can always PDF the PowerPoint Presentation and use the controls within Acrobat to create a presentation