Nec 2500a problems with Emtec DVD-RW 2x

Hy there! Well, im new around here and im here for the first time for the worst reasons, of corse. Ive got this almost brand new Nec 2500a and im using the Dangerous brothers firmware 2.15. I´ve been using this Emtec dvd-rw 2x for about 20 times or something like that, then, it just stoped to be recognized by my Nec drive, not even with diferent firmwares, the stock firmwares, hacked firmwares, etc, nothing could recognize the dvd-rw after i burned it, it simply says that i don´t have any media inside after i wait about 30 seconds with the IDE light on and my all system almost freezed. After all this tests i went to the computer store and bought an other Emtec dvd-rw 2x, i´ve placed it inside the drive, it recognized it, then i burn the dvd video that i wanted to burn, after the burn process, without any problems, the dvd media came out and all i´ve it was pushing the botton to make the media back in and after that, same problem, the IDE light is on for about 30 seconds, my system almosts freezes completly and at the end it says that i don´t have any media inserted. This is odd because i´ve used with success this dvd-rw brand and just like that it stoped working. If i put this dvd-rw inside a standalone dvd player it plays!! What kind of drive is this that cannot even recognized the dvd´s that burns and dvd players like my own standalone player can read? any suggestions?