[G4] Recommendation for SuperDrive replacement?

[joshua hough]

I have a SuperDrive in my G4 MDD dual 1.25 (purchased January 2003 from
Apple).  The drive is from Hitachi and has buffer underrun prevention.
Recently I cannot burn a single clean CD or DVD.  I have tested many of my
iTunes CDs in a variety of players and they either don't play, or quit
halfway through.  I burn DVDs in Roxio Toast.  These always fail partway
through Toast's post-burn verification step.  They play in a home DVD
player, but with frequent interruptions of picture scrambling.

Here is the drive info from System Profiler:
Device Revision:  D02E
Product:  DVD-RW GCA-4020B
Vendor:  HL-DT-ST (Hitachi)

I have tried several media brands and speeds, both name-brand and otherwise.
There is no apparent difference.  I have tried every speed setting from 1x
to max.  OS is 10.2.8.  iTunes and Roxio are up-to-date.  RAM tests okay.
No other apps are running while burning is in progress.

Does the drive need to be cleaned or replaced?  If so, what is the best
replacement right now?  Internal only, please.  I have AppleCare, but would
rather buy a newer, better drive than ship the whole G4 away to Apple.
Thanks,
-Josh