Interesting.  The textbook I'm using doesn't mention master slides until the
next chapter.  It gives the directions to create and save a custom template
when it introduces the use of design templates.  It made sense to me that it
should have been done on the master, but I figured I just wasn't aware it
could be done in the way they described.  We can save the design template and
it will show up in the design templates task pane, but it just won't apply.  
I thought maybe it had something to do with being on a network.  Maybe I'll
just alter the lessons a bit and hit this again when we discuss slide
masters!  =^)  Thanks!