Strange problem with my 3500A

Hello all,
Just registered on CD freaks and this is my 1st post. Unfortunately its to ask for help or opinions.
About 2 weeks ago I bought a NEC 3500A and installed it into my Win2K (SP4) system with no problems. I burned a back up of ‘mydocs’ with NERO 6, a few cd audio disks and also created a couple of video dvd’s using Nerovision 3… again with no problems (using datawrite classic 8x DVD-R’s) Yesterday I attempted to create another video dvd but although the software appeared to be burning nothing was happening on the disk! Eventually the software just knocked off and I went back to the desktop (no error messges and no image on dvd…very bizarre) Today I uninstalled then re-installed the drive… but nerovision keeps doing the same thing. I did burn a cd ok and appeared to burn another ‘mydocs’ backup… except my other dvd drive wouldn’t open it (windows said the disk had exeded the maximum allowed secrets???.. but it was the same backup as last time.) I also ran a speed test on NERO, it ran ok but I only got about 2x! By the way the drives read disks ok.
Any ideas on what the problem could be? If its a faulty drive I don’t want to flash the firmware as the vendor may not take it back. Also I don’t have access to another machine to test it on… besides it did work ok to begin with.
Sorry for the long post… any advice would be most welcome
Cheers. :confused: