now when i go to the advanced material room, as per lkendall's advice, i get this. And no matter how many times i change it, Poser either gives me the error or the render comes up with no textures anyway, eventhough i can see them temporarily in the material room

so, basically, Poser 8 doesn't like gaps in runtime names and doesn't like  the word "Poser" in any directory other than its own.
you will notice that it invariably changes the texture directory to either "POSER/RUNTIMES" or "Poser/Runtime"