I have exactly the same problem. One drive NEC DVD/RW (internal ATA) works fine - the other LITE-ON (Iomega USB external) says please insert disc....
I have made no software changes and this drive has worked well for the last 2 years......
I have Windows XP and am using a CDW / DVD R/RW. I have used it in the past to burn CDs. Tonight I am trying to insert a movie disc and no matter which movie I insert, nothing autoplays. In addition, when I click the drive in explorer, it says please insert a disk into drive d. I have tried a number of different movies to no avail.