DVD tray sticks when opening it

I received an original Xbox from someone and it seems to work very well, except the DVD drive likes to stick. What I mean by that is I press the eject button and it opens a tiny bit, sticks and goes back in. I found a way to temporarily fix this by hitting (not too hard) the system a fraction of a second after I hit the eject button and 9 times out of 10 it fixes the problem and it works great.

My question, is there a way to fix this issue so I don't have to whack the unit every time I change games?

Thanks!