It was only noticed today but may have begun many days ago. This Media Center Edition system has worked smoothly all along, through a number of upgrades and additions.
Drives: LiteOn 165H6S and Sony DRU-810A
Problem: Insert any blank DVD and it is seen as a blank CD by WinXP MCE and Nero Recode 2.
-- HOWEVER, Nero 7 itself will not have a problem recognizing it and burning it properly.
Background: Swapped/upgraded HTPC software packages recently. Among these, Nero 6, Sonic (patch for MCE), TheaterTek, PowerDVD.
The implication is that a software interaction may have caused it. I suspect something with the Sonic software could be at work. Hopefully someone will have a hint to offer.