If you try different bitmaps as page backgrounds, some of the bitmaps are
embedded in the saved presentation or presentation template, though they are
never used in the presentation nor in any of the styles. It's impossible to
remove the bitmaps embedded - they never show anywhere, they are just saved. Sun
Presentation Minimizer also doesn't remove them.

The only way to have a smaller file is to start all over again and choose only
one bitmap as a background. This is clearly a defect - unused elements shouldn't
be saved.

Attaching two versions of the same template: (1) the bloated one; (2) the normal
one.