My xbox 360 dvd drive won't play dvds?

I recently flashed my xbox 360 dvd drive so I can play backed up copies of the 360 games. I had a Liteon Drive and since I didn't want to buy a probe for it, I found a spare Samsung dvd drive from my broken 360. The drive works fine I haven't had any problems with it, but now since I flashed it the drive won't play normal dvds. It will read them then allow me to play them but while it is showing me all the federal warnings before you get to the dvd menu the screen comes up with the 360 symbol and says xbox 360 underneath it and the background is white. I can't do anything here I've tried clicking the main menu on but it doesn't work it just says "Action not available." Please help me. Thanks.