FIXED!!!
I didn't need a new drive after all. The laser was mis-aligned. Adjusting the height of the rails on my Samsung drive solved the problem of reading dvd movies but requiring 10 or more tries to read a game.
This is a non-modded xbox that was given to me by a friend after he returned it for repair 3 times. When I got it it had the Open Tray error which I fixed by installing a new laser. Thats probably when the rails got screwed up.
For you techies on the forum, I notice the rail adjusters are accessible from the top of the tray when a disc is spinning (if you run it without the top cover). That makes me think of connecting a meter or o-scope and spinning up some kind of factory calibration disc. Then adjust the laser until the instrument reads the optimum value. Does anyone know how to do this?
I hope this helps other people with the same problem.
I have exactly the same problem as you.. but with me the guilty is my modified firmware..
I "lost" the drive secure key that's exacly the same as the dashboard have, and unique, and now i have this problem, because i think its impossible to recover it by the dashboard and put in the drive again.
There's any kind of solution? If i buy a new drive i will have the same problem because the secure key will not match with the dashboard again..so what can i do?
Sorry my english but i am Portuguese.