No matter what I did, I couldn't solve this problem. I burned a dvd earlier and my NEC 2510A does not recognize the fÄ±iles in it. However, my laptop does recognize the files. I'have installed the latest firmware for it from its official site and the version is 2.18. When I put my dvd to NEC the windows explorer recognizes it as a blank CD instead of a DVD.
Any help is greatly appreciated.