Robin Hoods Playground

ok i flashed my 360 from 1.51 to 1.6 after the flash i went to turn on my 360 it gave me the 3 red rings then i shut it off then i turn it back on then it was normal so i decided to flash it again to 1.6 so i did went to turn it on it was ok anyone knows y it gave me 3 red rings after the first flas...