It's Rans here. (i'm at work and i don't know my password)
Well, i played around with the options in FCE Ultra. When set to PAL emulation, the whole screen is displayed. In NTSC though there's an option to change the first and last line of the drawing area. By default the first line is 8 and the last is 231. This can be really problematic with emulators. Do you know the "official" NTSC first and last lines on a real NES?
I hope that this is standard on a NES (with NTSC tv). If not then what a pain.