Try standing it up/lieing it down, If not your going to have to smack the top really hard when you click eject, Or, If you dont wanna brake your drive, You can take you xbox apart and take the DVD Drive's case off.

Thats what i usually do.

ok guys i fixed it! all i did was when i pressed open on the xbox i hit the xbox softly where the disc tray was and it opened thanks for all the help guys.