Trouble figuring out Master slides

I've been working on this for a few days and I give up.  Maybe I'm trying the impossible, I don't know.  I've created a master slide and I applied a specific theme and font.  I also setup the default player settings.  So then I create a new project and I tried copying the master slide to the new project and it changes my theme to something completely different and the font of the slide header is different than what I set the master to.  I also tried to import the master into my new project and that keeps the theme but not the font on the header.  When I copied or imported, my player default settings are wiped out.  What am I doing wrong?