Greenpois0n 4.2.1 jailbreak. cydia icon wont show up on loader ?

ok so after jailbreaking my ipod touch 4.2.1 , it all went smoothely until i tried installing cydia. i tried opening loader but the cydia icon doesnt show up. the screen just stays blank. i tried MANY times. is there anyway i can fix it ? i already tried redsnow as well, it takes forever and ive had some really bad reviews on it. i trust greenpois0n :)