I investigated the issues and found some help in this thread. A user, Galva, had suggested making these tweaks under Tools->Options in OpenOffice.org:

MEMORY – 30 steps, 128MB, 20 objects, 20MB per object, and remove after an hour
JAVA – Do not use Java
VIEW – Open GL, optimized output, dithering, refresh during interaction and hardware acceleration all ticked.

I had already made those changes to memory and the java runtime environment, but the view settings made a huge difference. The presentations actually run now! Thanks, Galva!

Coincidently, I was checking out the new Ubuntu brainstorm and decided to submit an idea — to optimize the OpenOffice.org default settings. I find I always make these tweaks on a new install. Unless there’s a really good reason why the settings are the way they are, they ought to be changed. It’s actually third in the office category now! If these tweaks helped you, consider voting for the idea on brainstorm.