Superdrive won't recognize blank DVDs

Question

This problem sounds similar to several I've seen here, but appears to be different, hence a new topic.
My PB has been in to Apple for repairs "several" times, and has multiple logic boards replaced and the DVD drive replaced at least 2x in the past 12 months.
I have the CD and DVD prefs both set to "ask". CD media immediately pops up the "You inserted a blank CD." dialog, so I know the drive is online and working. CDs with content load and run fine.
DVDs do not. Some DVDs burned on my 15" iMac read fine, while others get ejected or have read errors. Trying to burn off my nearly full internal disk to data DVDs, I've tried Disk Utility and Toast, and it doesn't matter. I get the same result. The program asks for a writable DVD; I insert a blank DVD; The drive churns for awhile; I hear a beep every so often while it is churning; The DVD is ejected without ever being seen by the Finder, Disk Utility or Toast.
I hadn't tried to burn a DVD since it last came from the shop, so I do not know if this specific drive ever worked for burning, but previous drives all worked fine. The fact that the DVDs never register anywhere I can see before getting ejected is just weird.
Is there some software config problem here, or should I just take the PB back to Apple and say, it doesn't work. Help. This is pretty frustrating.
It's not the DVD media, because it works fine in the iMac, and my other PB.
PB Ti G4 1Ghz 10.4.7 512MB/ 15" iMac G4 800Mhz 10.3.9 256MB   Mac OS X (10.4.8)  

Answer 1

Although, since when has a DVD that was rated for a higher speed NOT been able to be burned at a slower/lower speed?
Since always, if the data layer in the disc is sufficiently different from what the drive expects. In a high-speed drive, a disc with a high speed rating can be burned at any speed within the drive's range, often including very low speeds. But in a low-speed burner, high-speed media may not be usable at any speed, because its data layer is very different from what the drive was designed to work with. You may not be able to see the difference easily, but the drive does, and rejects the disc thinking it's defective.
Back before DVD drives and media were common, this problem arose all the time with people trying to read early CD-RW discs in the CD-ROM drives of older Macs: it couldn't be done. When the speed ratings of CD-R media skyrocketed to 48x and 52x, some CD-ROM drives couldn't read the high-speed CD-R media either, though that problem was less common.
When optical drives generally cost upwards of $200-250, it was hard to tell anyone that the simplest solution was to replace the outmoded drive with something newer and more capable. Now that you can buy a slot-loading high-speed dual-layer DVD burner with all the bells and whistles for under $100, it behooves anyone who can use those capabilities to go ahead and get one. As for me, I've never tried to burn a DVD in my UJ-815, and now that slow media are almost impossible to find, I probably never will. If I decide to burn more than one or two DVDs sometime, I'll replace my drive. You might save yourself some hassle by doing the same.
As for -RW media, I never bother with it: it's way overpriced and too often has problems. I've always had good luck with the cheapest CD-R discs on sale at Costco, Staples, etc. for about 15 cents apiece in large packages. I occasionally burn an archival disc using high-priced 200-year Delkin or MAM-A media, but for the most part, cheapies serve me fine.