Hi JC,
This sounds very similar to my situation. I have a new (October 08) HP Pavillion with Vista 64bit Home Preimum. I have read through most of the posts here, when I have checked the registry location referenced in
http://support.microsoft.com/kb/929461 and did NOT find either upper or lower keys.
I can burn CD/DVD's through Windows Explorer but cannot burn from applications such as I-Tunes or Quicken.
Your guidance is appreciated.