You might need to upgrade the firmware. My freind as a IOMEGA (rebadged NEC) DVD Burner. At first, it would not reconise certain brands of media. However, he's upgrade the firm where and he now have 50% succcess.
He can not burn on any media, it just that he might not be burning at full speed.
He can not burn on any media, it just that he might not be burning at full speed.