I purchased a Toshiba laptop a few months ago to serve as an audio jukebox. From the notes I made while investigating the services/apps/processes running on the unit, a process called RAMASST.EXE is used to kill Microsoft's CD writing software. From what I could ascertain, Toshiba wrote the app and wrote their own CD writing software. I poked around the web mostly out of curiosity and found it was used on a number of their notebooks, but did I not investigate further - I use the unit only as a jukebox and for no other purposes. RAMASST.EXE is in the startup folder. Perhaps you, or another app moved or deleted it.
This is just a wild guess on my part, but it might be a starting point for you to investigate. Also, take a look at the event logs (under administrative tools). (You don't perchance have one of the new models with the HDDVD - or whatever it's called - drive do you?)
Good luck!