SuperDrive slow burning solution
Apparently when you upgrade (archive and transfer user data) to a new OS (ie: Panther to Tiger) some of the files in the main Preference folder becomes corrupted, because if you create a new user and restart your computer under that new user and run Disk Utility, you will find that your SuperDrive's maximum burn speeds are restored. So Apple has assertained that the slow burn is a software issue, not hardware.
So what Apple got me to do was to reboot my computer back under the original user account name, then go to the Library folder and take out the original Preferences folder (./Library/Preferences) and place it on your desktop..DON'T TRASH IT. Then restart your computer. Once rebooted, launch Disk Utility and try to burn something with both DVD and CD mediums, and you'll see that their burning speeds will be restored to factory specs (in my case it would be 4X DVD and 16X CD). Quit out of Disk Utility. Drag all the contents of the original Preference folder on your desktop into the newly created Preference folder (./Library/Preference) WITHOUT REPLACING THE NEW FILES. Restart, and everything seems to be fine. Hope this helps.