I have the lastest BIOS (A14), drive firmware (10FE) and OS updates (WinXP Professional Version 2002 SP2) on my Inspiron 8600.  My optical drive reads everything just fine and can write DVDs.  However, it will NOT burn CDs.  The drive has burned CDs in the past.  I have tried various media starting with the ones I had (that worked last year), then have tried Imation CD-R 1x-52x, Memorex CD-R Pro 4x-48x, etc. without success.  Either the media is “not detected” or else it is “not writeable”.
 
I have tried burning CDs via Windows Explorer, Sonic, and InfraRecorder.
 
I have edited the registry to remove upperfilter and lowerfilter entries.  I have verified the drive's current Transfer Mode of Ultra DMA mode 2 and not PIO mode.
 
Help!
 
Thanks in advance.