I JUST CONNECTED AN AMD64 WITH ATI 256MB AGP CARD TO A JVC
26"HIDEF TV/MONITOR. HAD PROBLEMS WITH RESOLUTION, MOVED FROM S-VIDEO TO DVI/HDMI AND NOW HAVE MUCH BETTER RESOLUTION BUT CAN'T GET THE DISPLAY TO FIT SCREEN. CHANGED SETTINGS ON CONTROL PANEL THEY KEEP REVERTING BACK TO 720x480 I APPLIED CHANGES AND EVERYTHING,CHANGED ASPECT RATIO ON TV, DISPLAY TOO BIG FOR SCREEN. ALSO HOW DO I GET SOUND FROM MY COMPUTER TO MY HOME THEATRE?

For your display, have you installed the drivers for your card? If not, that is what is possibly preventing your screen from going higher than what you have stated.