i figured it out without having to alter that eeprom stuff, i had to go to my original dashboard unleashX and enable all display modes, then turn off force pal 60hertz then restart, and when it restarts go back to unleash dashboard and use file browser to boot the xbmc, then select the video mode (in my case 720p) and then reboot, then you should go back to the unleashX dashboard, when you do that, go to the official xbox dashboard and enable all the display settings there and widescreen support, reboot, and then after you do that to xbmc and find a option to change appearance in the settings menu, there should be a option there to change the display settings again, change it to 720p and quickly exit from that screen as in my case the screen goes black if you stay there for long and i can't press anything, after you have done than reset your console for the last time and it should stay permanently, that's how i got it to work.
now if anyone is stuck like i was with no solution try this and see if it helps.