Fullscreen prob

I’m trying to make a fullscreen OGL window. My screen rez is 1600x1200x32. I’ve created a popup window just fine, but when I try to set it’s dimensions to 1600x1200, the window simply doesn’t show up. What’s crazy is that all I need to do is set the dimension of the window to 1600x1199 and it works!! Anyone got any ideas?? Thanks!