After FireCore Install & Reboot My ATV2 Screen Is 4x3 Aspect Ratio

Hi, After the GP JB my Screen Still Looked Normal but after the FireCore Install and Reboot my TV Screen for the ATV Menu is Squished and became a 4x3 Aspect Ratio but after I restored my ATV2 then aspect Ratio become back to 16x9 and I'm currently using a 100% AUthentic Monster HDMI Cable connected to my TV. Is there a way to fix this issue via a menu setting or by SSH'ing into the ATV and running some commands? Please help....Thank you guys =)