Hi Satch;
I think I know what's causing the confusion, but unfortunately I don't know
of a way to do exactly what you're accustomed to in earlier versions :-(
In PPT 2004, for example, you were able to use what were called Design
Templates & you could apply a different Design Template to each slide in any
given presentation file. Those Design Templates were saved as .pot files
which appeared in the Change Slides> Slide Design section of the Formatting
Palette. Selecting one applied it to all slides in the file, but you could
also use Format> Slide Design [or right-click a single slide (multiple
selected slides in Slide Sorter View)], choose Slide Design... ],navigate to
where the .pot files were stored & when you selected one there were 2
buttons in the lower left corner labeled:
Apply to All Slides
Apply to the Current Slide
PPT 2008 will not allow for the "mix 'n' match" of multiple Slide Themes in
a single presentation. Further, the .pot files are not pictures (graphic
image files) so they can't be inserted as Backgrounds. Existing .pot files
are still usable in 2008 but they're recognized as Document Themes [more
below]. Document Themes [.thmx] apply to all slides in the file, not
individually to selected slides. Not only is this a difference in 2008 but
it's also a little deceptive because the Elements Gallery, the Format menu &
the contextual menus contain the term "Slide Theme" rather than "Document
Theme", which understandably suggests the 2 are totally different, but they
are intertwined. The term "Document Theme" only appears in one location --
the Formatting Palette.
A Design Template (.pot) from prior versions encompasses more than just a
background design. It also controls such aspects as character formatting,
color schemes, etc. PPT 2008 treats them more like Document Themes and
allows you to have more than one set of Masters in a presentation file or
presentation template. Each set of Master Slides can have a different Design
Template/Document Theme, but only one set of Master Slides in the file can
be applied at any given time... When you switch to a different Master all
slides in the file will be reformatted according to its attributes.
You can still use a different Background for any slide you wish, but if you
want to use a Picture it must be an actual image file format (JPEG, GIF,
PNG, TIFF, etc.)