Help with iWork Pages

When I first installed iWork the document would be centered on the screen and viewing it in fullscreen mode would have the document centered with black on both sides. While toggleing a few settings to try things out I realized the document was now shoved into the upper-left portion of the window, with large gray areas to the right and below. Also, when I activate fullscreen, the document is on the left half and there is a huge gray box on the right. I am wondering what setting I changed, and how to reverse the large gray catastrophe.